Transmission can drive in low 1 or low 2?

Can drive in low 1 or low 2 and can only drive in d if I go from 1 to 2 to d but while in d I don't think I'm going above 2nd gear still. Can't go over 35 MPH in it. No reverse at all, no overdrive. It always ran high RPMs. It did this several months ago except had drive and reverse just couldn't go over 35. Changed out fluid and filter in June and it fixed it. Well, the RPMs were still really high, but it drove at regular speeds. This happened a couple weeks ago, and I tried draining trans fluid and putting new in and it didn't help anything. Trans fluid was dark and smelled burned both times I changed it out. And when the filter was replaced in June there was a little bit of trash in the filter. We didn't take the filter all the way out this time to check it. Also, I have been having to add water directly into the main spot not the overflow on days I drive a lot of miles and its really hot outside. But the water in the overflow hasn't moved in months.