Macbook slow since installing Yosemite

Question

Problem description:
Since upgrading to Yosemite, my Macbook is very slow, especially when trying to open webpages.  I installed Yosemite because I bought my daughter an iPad and had to upgrade to Yosemite in order to do the Family Share thing.  Ever since, my Macbook has been incredibly slow (no issues with any other of our Apple devices or with using my work-issued PC, so it's not my WiFi connection).  I'm wondering if there's a bunch of junk on my system--I use it mostly for email, internet and storing photos and I see all the things in my EtreCheck that were "killed due to memory pressure."  Any help would be greatly appreciated.  Thanks.
Here are the results of my EtreCheck:
EtreCheck version: 2.1.5 (108)
Report generated January 10, 2015 at 8:56:41 PM EST
Click the [Support] links for help with non-Apple products.
Click the [Details] links for more information about that line.
Click the [Adware] links for help removing adware.
Hardware Information: ℹ️
  MacBook Pro (13-inch, Mid 2012) (Verified)
  MacBook Pro - model: MacBookPro9,2
  1 2.5 GHz Intel Core i5 CPU: 2-core
  4 GB RAM Upgradeable
  BANK 0/DIMM0
  2 GB DDR3 1600 MHz ok
  BANK 1/DIMM0
  2 GB DDR3 1600 MHz ok
  Bluetooth: Good - Handoff/Airdrop2 supported
  Wireless:  en1: 802.11 a/b/g/n
Video Information: ℹ️
  Intel HD Graphics 4000
  Color LCD 1280 x 800
System Software: ℹ️
  OS X 10.10.1 (14B25) - Uptime: 9 days 2:22:51
Disk Information: ℹ️
  APPLE HDD TOSHIBA MK5065GSXF disk0 : (500.11 GB)
  EFI (disk0s1) <not mounted> : 210 MB
  Recovery HD (disk0s3) <not mounted>  [Recovery]: 650 MB
  Macintosh HD (disk1) / : 498.88 GB (414.23 GB free)
  Core Storage: disk0s2 499.25 GB Online
  HL-DT-ST DVDRW  GS31N 
USB Information: ℹ️
  Apple Inc. FaceTime HD Camera (Built-in)
  Apple Computer, Inc. IR Receiver
  Apple Inc. Apple Internal Keyboard / Trackpad
  Apple Inc. BRCM20702 Hub
  Apple Inc. Bluetooth USB Host Controller
Thunderbolt Information: ℹ️
  Apple Inc. thunderbolt_bus
Gatekeeper: ℹ️
  Mac App Store and identified developers
Problem System Launch Agents: ℹ️
  [killed] com.apple.CallHistoryPluginHelper.plist
  [killed] com.apple.CallHistorySyncHelper.plist
  [killed] com.apple.cmfsyncagent.plist
  [killed] com.apple.EscrowSecurityAlert.plist
  [killed] com.apple.printtool.agent.plist
  [killed] com.apple.scopedbookmarkagent.xpc.plist
  [killed] com.apple.security.cloudkeychainproxy.plist
  [killed] com.apple.telephonyutilities.callservicesd.plist
  8 processes killed due to memory pressure
Problem System Launch Daemons: ℹ️
  [killed] com.apple.awdd.plist
  [killed] com.apple.ctkd.plist
  [killed] com.apple.ifdreader.plist
  [killed] com.apple.nehelper.plist
  [killed] com.apple.periodic-daily.plist
  [killed] com.apple.periodic-monthly.plist
  [killed] com.apple.periodic-weekly.plist
  [killed] com.apple.tccd.system.plist
  [killed] com.apple.wdhelper.plist
  [killed] org.cups.cupsd.plist
  10 processes killed due to memory pressure
Launch Agents: ℹ️
  [failed] com.divx.dms.agent.plist [Support]
  [loaded] com.divx.update.agent.plist [Support]
  [invalid?] com.oracle.java.Java-Updater.plist [Support]
Launch Daemons: ℹ️
  [loaded] com.adobe.fpsaud.plist [Support]
  [loaded] com.microsoft.office.licensing.helper.plist [Support]
  [invalid?] com.oracle.java.Helper-Tool.plist [Support]
User Login Items: ℹ️
  iTunesHelper Application (/Applications/iTunes.app/Contents/MacOS/iTunesHelper.app)
Internet Plug-ins: ℹ️
  Flip4Mac WMV Plugin: Version: 3.1.0.24   - SDK 10.8 [Support]
  FlashPlayer-10.6: Version: 16.0.0.235 - SDK 10.6 [Support]
  OVSHelper: Version: 1.1 [Support]
  DivX Web Player: Version: 3.2.4.1250 - SDK 10.6 [Support]
  CouponPrinter-FireFox_v2: Version: 1.1.10 - SDK 10.5 [Support]
  Flash Player: Version: 16.0.0.235 - SDK 10.6 [Support]
  Default Browser: Version: 600 - SDK 10.10
  QuickTime Plugin: Version: 7.7.3
  SharePointBrowserPlugin: Version: 14.4.6 - SDK 10.6 [Support]
  Silverlight: Version: 5.1.20125.0 - SDK 10.6 [Support]
3rd Party Preference Panes: ℹ️
  Flash Player  [Support]
  Flip4Mac WMV  [Support]
Time Machine: ℹ️
  Time Machine not configured!
Top Processes by CPU: ℹ️
      58% WindowServer
      5% Photo Booth
      3% VDCAssistant
      1% com.apple.WebKit.Plugin.64
      0% fontd
Top Processes by Memory: ℹ️
  86 MB Safari
  64 MB Finder
  43 MB WindowServer
  39 MB com.apple.WebKit.Plugin.64
  39 MB Mail
Virtual Memory Information: ℹ️
  36 MB Free RAM
  743 MB Active RAM
  702 MB Inactive RAM
  1.07 GB Wired RAM
  6.24 GB Page-ins
  684 MB Page-outs

Answer 1

Try these in order testing your system after each to see if it's back to normal:
1. a. Resetting your Mac's PRAM and NVRAM
    b. Intel-based Macs: Resetting the System Management Controller (SMC)
2. Restart the computer in Safe Mode, then restart again, normally. If this doesn't help, then:
Boot to the Recovery HD: Restart the computer and after the chime press and hold down the COMMAND and R keys until the Utilities menu screen appears. Alternatively, restart the computer and after the chime press and hold down the OPTION key until the boot manager screen appears. Select the Recovery HD and click on the downward pointing arrow button.
3. Repair the Hard Drive and Permissions: Upon startup select Disk Utility from the Utilities menu. Repair the Hard Drive and Permissions as follows.
When the recovery menu appears select Disk Utility. After DU loads select your hard drive entry (mfgr.'s ID and drive size) from the the left side list.  In the DU status area you will see an entry for the S.M.A.R.T. status of the hard drive.  If it does not say "Verified" then the hard drive is failing or failed. (SMART status is not reported on external Firewire or USB drives.) If the drive is "Verified" then select your OS X volume from the list on the left (sub-entry below the drive entry,) click on the First Aid tab, then click on the Repair Disk button. If DU reports any errors that have been fixed, then re-run Repair Disk until no errors are reported. If no errors are reported click on the Repair Permissions button. Wait until the operation completes, then quit DU and return to the main menu. Select Restart from the Apple menu.
4. Reinstall Yosemite: Reboot from the Recovery HD. Select Reinstall OS X from the Utilities menu, and click on the Continue button.
Note: You will need an active Internet connection. I suggest using Ethernet if possible
            because it is three times faster than wireless.
5. Reinstall Yosemite from Scratch:
Be sure you backup your files to an external drive or second internal drive because the following procedure will remove everything from the hard drive.
How to Clean Install OS X Yosemite
Note: You will need an active Internet connection. I suggest using Ethernet if possible
            because it is three times faster than wireless.