Q: My car reverses but stopped going forward while I was driving.

I ran errands during the day and had no issues with my vehicle. All dash lights come on when I start it up to check the system, but no lights stay on. It has never missed or stalled. I was continuing my errands when I stopped at a red light and when I pushed on the gas again, it accelerated but didn't move. It moves backward when I put it in reverse just doesn't move forward at all. I have checked all fluids and done an oil change. It has no leaks but I do not know how to change transmission fluid in a sealed system and I believe it may be low. Someone said it could be a blown fuse. Is that true? Or does it sound like the transmission is blown? I'm hoping it just needs fluid but I don't want to tow it to a mechanic yet without a little advice on possible issues so I know what to expect from expect. It still starts up perfectly and sounds really good without any warning lights about issues on my dash. It also still isn't knocking, missing, or leaking.

My car has 90000 miles.
My car has an automatic transmission.