Winstrol and water retention

I have been on Winstrol (oral form, 2x25 mg per day) for two weeks now, out of a program of 6 weeks. Muscle gains are pretty good, much faster than expected, in fact. However, I have recurring headaches, cannot sleep well anymore (and I had never experienced that in my life...), and I put on a lot of weight (8 lbs, per week), possibly from water retention and muscle gains. I am on a fairly serious cardio program besides my usual strength workout (5 hrs a week of intense cardio), but I am really surprised not to lose any weight or gain any definition at all. I am just bulking up, which is great for martial arts, but not for wearing business suits.
As far as my sex drive is concerned, nothing to report so far. If I keep putting weight on like that for the remaining 4 weeks, I think I will not have to worry about my sex drive anyway as I will certainly not be able to score anymore ;-)
I have experienced some bouts of nausea, and I feel generally bloated.
My temper is usually fairly volatile, and it has not getting any better recently. I am not sure this can or should be attributed to Winstrol, though.