What Happened 12/30/17 Last Recieved Transaction into Bitcoin Core Wallet
I have found a different receiving address within my wallet that is not mine.


If it is in your wallet then by definition it is yours (unless you added it as a watch-only address which I doubt in this case).

It could be a change address, automatically generated by your wallet to receive change from another transaction you sent. Without more info it is hard to say though. 

The -whitelistforcerelay=1 parameter is nothing to worry about, that only relates to the relay of blocks between peers and is nothing to do with your transactions or wallet.