This might sound a little wacky at first, but looking at your pictures in your profile and then at your dietary schedule...I'm going to say that I think you need more fat in your diet. I know that it's been highly stigmatized against in today's society, but the facts are there. Fat gives a high boost of energy. I'm not saying go eat out at Mickey D's every day, but having more red meat in your diet wouldn't hurt.
Personally, (since you didn't really say exactly which exercises you do other than bench and squat) I'm going to say that you don't need to do 5 sets. If at all possible just do two sets or so with 6-8 repetitions MAX, as in you are physically unable to do another repetition past that for that set.
Another thing you may want to take into account is a systems change. After a period of lifting, your body becomes used to the regimen, so you need to "shock" it into gear. Systems changes are really easy to implement into your workout routine, but I'm going to warn you that you'll be sore as a bitch after the first change if you do it properly.
Some system changes:
Increased negative phase- Example: When doing a curl, you lift the weight normally, but on the down i.e. negative phase, you relax your muscles slowly, giving yourself two or three seconds.
Inverted Pyramid- Start off with a low weight, do six reps or so, then increase the weight and increase the reps until you work until muscle exhaustion (Caution. Really easy to injure yourself using this method, I would recommend only using freeweights or machines while using this system)
Ladders- Really basic, same rep amount, different weights. No explanation is really necessary
etc. etc.
Also: There's a whole bunch of weightlifting theory, but I'm going to take a page out of Arnold's book, where you work out until you feel "the pump," where the blood rushes to the area where you've been working out.
YouTube - Arnold Schwarzenegger - The Pump
Which reminds me, if you notice while he's doing those curls, he's using the cheater method instead of only bending his elbow, he uses the lateral motion of his body to help push the weight up, so while proper form is good to have and reduces the risk of injury, using the cheater method, you can have greater increases of strength and larger muscle mass.