Chug a Chug a

OK back on the train AGAIN. Who life isn't this the story of? I am sure everyone feels the same. every week, even day for me I start over and have to remotivate myself. I wonder if there ever come a time/day/amount of time spent working out when you finally just do it and dont have to talk your self or trick yourself into it.
I am kinda frusterated right now. my knee cap is killing me and so lunges and the bike and alot of other things have been really hard for me to do. I just want to get my good workout in so I can get my tones legs back. ARG! I haven't had that for over 4 years. My real goal?? A flat belly. I have never had this since high school and that was just out of the fact that I was young and really pre-pubescent for the most part!
So I worked out 3 times last week and yesterday, I am on a roll and loving it!
My goal is to be 10-13 pounds lighter by May.... good luck to me!