It looks like you and I are about the same starting weight. I've lost the weight before, and I assure you, it can be done....
Now, I'm past the 21 mark... I'm 27. But I've been there! and not too long ago either

I am married and raising my first child. I SWEAR my husband stumbled into my life the DAY I vowed to only worry about me.

Men will come later. Forget about them and just focus on you.
If you would like to PM me, I'm more than willing to lend an open ear. Like I said, I've been there before, my early 20's were pretty rough... and maybe you need someone just a *little* older, to remind you that you will come out okay on the other side.