Hello, I was on zyprexa for about a year, I found myself in pretty much the same situation, I was on 7.5mg sometimes took 10mg or more but I used to try just 5mg. At 5mg I still gained a lot of weight, my appetite was huge and my motivation was so low I couldn't exercise. I was having mixed episodes and zyprexa was excellent for me during a crisis as it just knocked me out and stopped my rages.
When I was pretty much ok it was a terrible drug for me, it maintained me but only because I had no energy, but I still continued to have episodes.. eventually I secretely came off it, I wasn't on anti depressants but it caused me to go hypomanic straightaway and then worse, nearly lost everything.. I saw my pdoc and told him I had stopped taking it and was no way I would take it again, he didn't understand why the weight gain was such an issue for me but he'd rather have me on meds than not so he changed me onto depakote... they all tend to make you gain weight but zyprexa is one of the worst, I think a lot of people would agree.. if you've been on it a year you've given it a fair shot so see your doc and ask for something else x