TLTR; trans messed up how what who do I do? Rebuild? Buy a rebuilt? New? I’m very very new lexus’s (to cars)

I’ll try to make the story as short as possible but won’t miss essential detail. Basically, this (1993 Ls) is my first car, I bought her maybe two months now. She started slipping a week and a half into owning her and I brought her to the shop they told me it was A trans leak and put dyes to find it but no trans fluid, besides the point. She was leaking very bad and they told me to drive her to get the dyes to go, so I was slowly adding fluids (she was bone dry coming out of the mechanics and they were closed and I called the next morning and they said it was a closed system so they didn’t add any) and slowly driving around my neighborhood. She gets stuck in reverse. I’m low budget and trying my best to find a good option to be able to get my transmission issue fixed. I’ve brought it to two places to find what could be wrong and they both said rebuilds, do I go with a rebuild or find one online? (Can’t really) or go to auto zone (my good friend told me to get one of theirs) just any and all recommendations. And I know I might get a couple comments on here about just sell it etc, I would believe me, but my dad left me a ‘93 before he moved on and it was one of his first cars so getting rid of it will be my last option.

 

From a practical stand point, most often the time and effort to find exactly what the issue is inside the transmission is often more costly than to just swap in a rebuilt unit. This is especially true if you're going to have to pay someone else to do the work.

 

Within the first two months of driving this car, have you done anything to it?

 

nothing that would mess with anything. Just interior deep cleaning and unplugging my broken radio mast. That’s it.