need trans help! completely lost on this one.

ok so i posted a while back about carb problems after a light rebiuld

when i got the engine up and running i drove the car for about 2 weeks, I had ZERO problems while driving other than running a little rich

up until one day i stopped at a stop sign on the way to class and when i hit the gas my engine only revved, when i switch to reverse it could take anywhere from 2 to 20 seconds to engage. Drive would not engage AT ALL

the next day i started it up and i was able to drive fine for about 10 min until the trans started acting the same way.

• the trans shifts through all gears when working
• the engine runs fine no overheating
• the trans fluid is a healthy red

Im lost on this one guys!!!