FRUSTRATIONS!!!!!

Ok...so here are my frustrations, which are probably fueled by my hormones right now.

• NOT LOSING WEIGHT FAST ENOUGH...Is this God's way of teaching me patience? Yes, probably, but when is it time to see a doctor? I added up my calorie loss due to exercise and I should be losing 1 lb every week. That is not happening. I look at my calorie intake and it's VERY rarely over 1800 calories/day. Why am I not losing weight like everyone else?
• OTHER PEOPLE ARE LOSING MORE WEIGHT THAN ME IN LESS TIME...I ran into a friend of mine who mentioned that she and another friend of mine have lost 18 and 21 lbs each in the span of a few months. I was immediately thrown into depression. I've not lost 18 lbs in over a YEAR!!!! What am I doing wrong?

This all makes me want to throw my hands up and quit. Truly it does. If anyone ate what I eat and work out like I do they'd be losing weight super fast but not me. It really does make me want to cry. I give my diet and exercise to God every day. I give Him all the praise for the weight I have lost. I will continue to praise Him through all this but is it time for a professional? Is it time to do something different?

I would appreciate some prayer from ya'll. thanks :)