transmission trouble '89 accord

when i first got the car i noticed that sometimes when in neutral or with the clutch in the engine will rev up to 2 rpms, drop back to 1, then rev up again over and over. It hasnt been a problem and my dad said it was probably just the timing and not a big deal. Recently it also started staying at 2.5 rpms whenever I idle. So I either get the first thing or a solid 2.5 rpm idle. Today I was at the ATM idling and I started smelling something not so great. I drove over to autozone and the guy helped me figure out it was most likely low on transmission fluid which would be easy to remedy or i might have to empty all the fluid out and refill it fresh. The problem is I cannot release the bolt on the transmission check/fill. I am not sure if I am missing some step before trying to loosen it but I have tried some break-up catalysts and gentle tapping with the hammer and no matter what the thing wont budge. I am just wondering if there is some catch I am missing OR if my whole approach is misguided and it is some other problem altogether.
Thanks,
alex

*EDIT: the car is manual and I am pretty sure I have the correct bolt as it is 17mm and I read that was its size somewhere else on the boards here.

Put some grunt into it.

hehe 3 other people besides myself have had a go at it. I tried more penetrating catalyst today and jacked it up higher so i had more room to leverage. Im putting so much grunt into it that the whole transmission is moving. I even check another bolt to make sure im turning it the right wat and I am (counter clockwise). Our next option is to try heating it up I guess. This is getting ridiculous.

Use a breaker bar or put a pipe on the wrench your using. If you have a torch go for it, cook the fucker but dont get it red hot. It must be corrosion because if you tighten them to much you crack the housing.