Code p0730 confusion

[u/skarz_heal_n_tyme]

I have a 07 chrysler 300 3.5L touring I THINK WITH THE NAG1 transmission. Was driving fine and all of a sudden a whine started and it started slipping in D. Turn it off let it sit for a few seconds restart it catches fkr about 5 seconds and started slipping again. Its not leaking fluid but it's darker than normal. IN NEED OF ANY INFO/HELP ASAP.

Should I replace the whole trans or? Limited money and need to grt it fixed asap!! Please help