Wake up my mind symptoms and conditions

I had taken Wellbutrin SR 150mg 1x a day for over 2 months without noticing any effects. Now I am on Wellbutrin XL 300mg 1x a day for the past 3 months and have been experiencing sleeplessness for almost a month. I can get to sleep OK, but after 5 hours at most I just wake up - my mind is alert and I just have to get up. This is very tiring and makes for a long day. My "normal" sleep is about 7 hours.
I have also noticed weight loss, about 10lbs in the past month or so, without any decrease in appetite.
I am taking Wellbutrin for smoking cessation - I have noticed less of an urge to smoke and have been able to go for a longer time without a smoke, although I have not quit yet.