He's telling you how he feels so you should accept his feelings. In other words DON'T say "you shouldn't feel that way,- of course you're fine", etc...
Positive Actions
Then with HIS and your suggestions, help him take positive actions on each of the areas you mentioned to help him change them for the better. If he helps with coming up with suggestions on what to change to correct each issue, then he will be more likely to do folllow through on the action. Taking an action on a problem will create self esteem in him.
He can get on a weight loss plan, read up on the internet about how to stop bedwetting, and start a good tutoring program on reading and writing etc.
Remember to let him suggest how to correct the problems. Kids can usually come up with good ideas. Try using some of his ideas even though they don't sound helpful. This will make him feel important.
One of the things I had to do when my son was diagnosed with a disability back in grade school was always control the amount of mail seen by him from the school that mentioned the word "disability". If your child hears everyone telling him he has a disability then he will start acting out the part. Usually to the extreme.
Through the years I discreetly hid papers from school mentioning disability and downplayed any teacher telling me about his so called "disabilty", - especially when the teacher would want to talk about it in front of my son.
My son is graduating from high school this year and he made it through because he believed in himself and was able to excel even thought others thought he wouldn't.
I wouldn't take him to a counselor just yet because this might encourage the idea within himself that something is "wrong" with him.
God Bless