I was on the DepoProvera shot for several years as well, and I'll say outright it was for birth control. I started it just after my marriage, stopped it to have a child, then started back. I loved it. No unpleasantness each month. Wonderful. But it turned me into a raving bi***. It also made me add on the pounds. Since I stopped the shots I've been much happier, lost 13 pounds, and, unfortunately, gone back to dreading that time of the month. Great shot, not for me. Very, very glad it's helping you. Obviously no medication is right for everyone.
My complaint with DepoProvera is that it is libido suppressing as well... I'd joke that it kept you from getting pregnant by making you not want sex in the first place!
And it's not imaginary. It was used in a test awhile back on ~male~ sex offenders to decrease libido.