I'm having the same problem so your not alone. I have found though that he is really just teething, and going through a growth spurt so he is hurting and just out of sorts cause he doesnt know what to do. Poor guy.
I give mine tylenol, and Hylands Teething Gel and it really does help and makes him a much happier boy. If you think he is teething or if he is really cranky there is nothing wrong with giving him some tylenol.
Also, I give him different things to play with. Maybe he's bored of his toys?
I switch out his toys every now and again, and he forgets about the ones I put away so when I give them back its like hes getting new toys and gets so excited. My son just loves kitchen utensils, like spatulas and spoons haha.
Also when I am trying to clean up or something, I put him in his high chair and give him a bunch of puffs, the Gerber kind, they have a million different flavors, also yogurt puffs are a hit with mine too and he is quiet and happy, because he can do it himself and I can get things done.
You say he wakes up frequently so I am thinking he is over tired, and not getting enough real sleep. When he wakes up at night, quietly go in, and give him a pacifier and let him self soothe a bit and see if it works. I bought the book "The no cry sleep soloution" and it really helped me out a ton.
My son wasnt sleeping well either until I got that book and now he sleeps almost all the way through the night.
He needs a schedule, children cant function properly unless they have a schedule. They crave structure so give it to him.
When he wakes up feed him, then play then when he starts rubbing his eyes then its time for a nap, then when he wakes try giving him a snack, like fruit or more puffs etc. Then play, then maybe afternoon nap, then after that, its solid food, then bath then rock and read, then bed for the night.
Try a routine for a few days and adjust where you feel its needed.
Everything will be okay try not to stress, when you stress he can feel it and he gets stressed too. Just take it one minute at a time and do your best. Your doing great just hang in there :) Just try different things until something works for both of you :)