The winny is probably not what made you gain 10lbs, you probably upped the cals and worked out harder, especially if you took it 2 times a week and this was during your teens. If I was you, I would clean up the diet and try to gain 10lbs naturally because at your age it can easily be done. If you decide to take gear, I would reccomend a simple test only cycle. You can gain as much or as little as you want with your diet. I have a buddy that gained 21bs from 10wks of test only at 500mg wk. and my other bro gained only 12lbs from the same cycle with a leaner diet. Dont run any other compound without test, like winny only or eq only because it will be more harmful than beneficial in the long run. A cycle of test only would look like:
wk1-10 500mg test
wk1-16 10mg nolvadex ED
wk13-16 Clomid pct