I feel like retin-a isn't doing much for my acne marks and uneven skin tone, my pimples and breakouts have been reduced a lot. its been over 4 weeks. ?

Peels or resurfacing: A series of chemical peels and/or resurfacing techniques will be needed.

Persistence : It will take time. Especially for acne marks. Scars that have left pits will not improve much at all and usually require laser resurfacing. Uneven skin tone should eventually improve quite a bit though.

Won't touch scars: Retin-a is great stuff especially when there are blackheads but it won't touch scars and won't alter postinflammatory pigmentation. I'm very glad you've gotten a good result. Adding a topical antibiotic such as Clindamycin may help also.