MurphyLaw

So here it is. I own a 1995 Ford F350 7.3l turbo diesel dually 2WD with 300,000+ miles on it and E4OD trans. before taking it on its first long drive to Pennsylvania from North Carolina I checked all fluids and found the transmission fluid low and added DEX/MERC to the proper levels. as soon as I hit the highway it fail to shift past 3rd and jolted when it shifted from 1st to 2nd. reverse and neutral worked fine. I took it home and cleaned all the connectors on the transmission. I have not pulled codes it does not have obdII. I will pull them as soon as I can. when I tried to drive it the other day it had the same issue but now it takes higher rpms to make it move and slips in and out of gear at low speeds and idle regularly. it will stay in first for a few seconds then no gear on and off until it gets going. my overdrive button on my shifter doesn't work and my shifter is misaligned so when its in drive the shifter is actually on 2 its been this way for awhile with no issue. I also just had to replace the headlight switch and dimmer because it burned up. I could really use some insight and you guys seem extremely knowledgeable on this transmission. anything you could tell me would be very much appreciated.