95 Toyota Corolla

About 3 or 4 days ago. Overdrive light flashd on and off repeatedly, figured I might have accidently hit the little button while shifting. So I was very careful. Next 2 days went home from work and car went back and forth between "I have go forward power" and out. Barely made it home last nite. And now have parked it at where I live. Gave some gas and kinda clicked back in to where I could get into the parking lot of the townhouses. PLEASE EMAIL ME as I may never find this again. Several told me diagnostics would cost about 90.I am a waitress at a waffle house. PLEASE HELP! I am scared the tranny is going. But am told it could be a computer prob. Many possible. Car starts and all and keeps running. Esplendour@hotmail. Com. Anything you can do would be appreciated. God bless. Fredericksburg va. Bus service here too is awful!