1996 Chevy Camaro No one can figure out my car. Can you?

I have a 1996 Chevy Camaro, v6 3.8. This is complicated, but I want to explain it all so maybe someone can link everything together and figure out my car. About a year ago my Check Engine light came on and it said it was missing on cylinder 5, I had the plugs and wires changed. The light went off. Then if you would go and make like 2 or 3 trips in a short period of time, after a few start ups. The car would just not start, and would not start for a few hours, then all of a sudden it would start fine. It went on like that for the whole year and still does it from time to time. But now what it normally does if you start it a lot in a short period of time is that it will start, and back you up out of the driveway or whatever, but as soon as you start going forward and push the gas it spudders like it is going to stall then just all of a sudden takes off and drives fine. Unless you try going up a hill. It spudders the whole way up it. Quite frequently now when it is spuddering the check engine light comes on and it always said that it is missing on cylinder 5. I have had the coil pack and the module changed. When it is spuddering you can push the gas all the way to the floor and it does nothing. My mechanic just will say a list of things he could do, but he really doesn't know what is wrong, and he doesn't listen to the whole problem, because he works on cars as a side job and really doesn't want to take the time and figure my car out. But he is cheap and all I can afford right now. He says my problems now have nothing to do with when it wouldn't start like it used to do, but I never had that probelm fixed, so I assume it has something to do with it. The car can't fix itself. It also now will spudder and the check engine liight comes on (saying a misfire) when it rains hard or you drive it through a car wash. I just need help and I don't have a ton of money to spend. I feel all of the cars problems are intertwined with each other since I have never fixed it, the probelms just keep progressing. It used to do this one in awhile, now it does it almost everyday. Oh, I almost forgot, the check engine light also comes on (when check with a scanner it ALWAYS says misfire cylinder 5) when you turn the heat or a/c on. When the light comes on, with all of the different things that makes it come on, (heat, rain, mutliple starts) the car ALWAYS acts the same it spits adn spudders and you think it is about the stall. Sometimes it will just all of a sudden quit and run fine and other times it has to sit overnight before it acts normal. PLEASE someone take a few minutes and think this through and bring me some answers! Thanks for trying!