Speedometer quit, transmission not shifting right

The van sat unused for about two months. When I wanted to start it, after a few cranks, battery gave up. I hooked up my battery charger to battery on " cranking mode, 225 amp " and started the engine. Shortly after starting to drive, I noticed that speedometer was acting crazy, 70 /90 mi an hour driving in the residential area. Then, when I got on a bigger road, I noticed that the transmission was not shifting right. Also the abs light came on in the dash. Than the speedometer quit completely. When I reached approximately 45 mph, engine cut off ! When speed dropped some, engine cut back on. I think that the engine is in some kind of limp mode. Won't go over about 45 mi/hour. Had it checked for any codes with a obd ii. No codes ! I replaced the VSS sensor on the back of the transmission, noting happened. Acting the same. Also I noticed that the odometer, some how changed and now shows km instead of mi . I am mechanically savvy, but separated from the profession for more than 30 years. I would appreciate any suggestions/help at this time. Thank you. ( All fuses are okay. Engine runs good until the van riches about 45 mph. Then feels like engine lost power/no acceleration, until speed drops and then catches on again. Transmission shifting is bad all the time. )