First off, even though you didn't gain strength, you lost weight, so you gained weight for weight strength, which is good, just not absolute strength.
Second off, I don't think 2 days of lifting is enough for significant strength gains even if it is a full body workout. I do full body lifts every other day so about 3 or 4 days a week and that seems to work for me.
Third off, if ur about 6 foot 4, chest lifts like the bench press are hard for you since ur arms are so long. 6 foot 9 NBA basketball player Kevin Durant can't bench press 180lbs.
Hope this helps...