Ford Repair: Ford F150 98, 2 quarts, step dad

Question
Ok Tony, I was driving my truck back home on a long hwy. When all of the sudden my overdrive light started blinking on and off. I pulled over because I smelled something funny and was hopeing to god it wasn't my engine. I popped the hood and checked my fluids and found out my truck was real low on oil. It has a oil leak that was never fixed by my step dad, the trucks his i just borrowed it for an arron. I turned around to the nearest gas station and bought some oil. I got 10w-30. I put one quart in before i read the sticker that read 5w-30 =[ I went back and got the right kind, i put in 2 quarts of 5w-30 and one of 10w30, and hoped it wouldn't mess up the engine. I drove it a while longer before i noticed the RPM's were hitting high levels and it was getting harder and harder to accelerate so i pulled over about 20 minutes from my town and had to hitch a ride back home. whats wrong with my truck? Any idea of what the problem may be? If so, i would appreciate it deeply if you can help. I don't want to disappoint my old man, and told him i totaled his truck.... So yeah, thank you for your help.

Answer
Hello Seuss, The overdrive light pertains to the transmission, not the engine. Your RPMs are going up because the transmission is slipping and not keeping the gear desired engaged. You'll have to figure out what is wrong with your transmission in order to fix it and get it back on the road again. Hope this helps Thanks Tony