getting harder to exercise as I lose???

Help!  I work out 4-5 times a week for a minimum of an hour (usually more like 2.5 hours) and I do a variety of cardio and weights.   In the past 2 weeks I have noticed I am having difficulty with all of my weight exercises...whether it is a machine or free weights.  I am really struggling and neither my reps nor my weight amount has been increased.  Someone suggested that I am having trouble because I am getting smaller.  Somehow this didn't make much sense to me because I am supposed to be building muscle.   Any thoughts or advice will be greatly appreciated! Christine

Not really sure.  Is there someone you can talk to at your gym?

When you weight train, you do a little bit of damage to your muscles.  Make sure you're eating enough protein.  Do you know your protein intake right now? I'd also make sure you're focusing on your form.  Are you isolating the muscles you're working? 

My protein intake is above my 76g daily goal.  When I work out hard, I make sure to have an extra shake just to be sure.   I will have my trainer go over my routine with me again to make sure I am doing things correctly...I usually have partners with me and we watch out for each other, but who knows, maybe I'm doing something wrong no one sees. Thanks for the input!