My sons have been there; I've been there, done that.
My father used to joke (a little tease) that we were trying so hard to get our son(s) to talk and, just think, soon we would wish we could get him/them to shut up! ;)
I agree with a lot of the others who have posted: try to let the potty training wait. You may be stuck, though, if your son is in a child-care facility who only accept 3-yr-olds who are potty trained. It sure was a strain on me until I found other care (an in-home day care, for instance) who were willing to work with me and with my son.
As far as the talking, I could tell that hearing was not a problem, but getting your pediatrician to refer your son to an audiologist isn't a bad idea. At the least, the documentation will be there.
Also, I realized that I was anticipating almost all of his needs. I knew he would soon be hungry and would make a sandwich; I knew he liked cookies and would let him get some out of the pantry; and other little things. What the Early Intervention people told me was to ask him to ask for what he wanted; to start expressing that he was hungry, etc. Now, I didn't demand all of that all at once. Some sign language helped us get "over the hump" and I would suggest things.
For instance, saying something like, your body looks like it is getting hungry. Does your tummy feel like you might be hungry?
Or, letting him say "kee" for cookies but insist that he attempt to say it before giving him the cookies.
I stopped letting him get by with just grunting and pointing. Whenever I saw him trying to get my attention and pointing (I knew what he wanted), I would help him express what he wanted instead of just giving it to him. I might say "What is it? Do you want something to eat? Can you point to it for me? (sometimes I had to lift him up so he could point directly at the package of cookies and not at the package of crackers) Oh, those are cookies, say 'cookies'." That was when it was okay to say 'kee' for cookies, at least in the beginning.
I would also start asking him to make a choice; like to say cookies or to say crackers; water or milk; etc.
More will come as he continues the speech therapy and you continue to ask him to apply his verbal communication at home.
Take a deep breath and believe that all this will get better. He most certainly won't stay 3-yrs-old! ;)