Car dies if I’m not giving it gas...

So I was out a few nights ago and I was about to head home and got in the car and it started up fine. Turned on my lights since it was night. The lights were very dim but I didn’t worry to much. I was fixing to pull out of the parking lot and I pulled up to the stop sign and then it just sputtered out and died. I started it up again and made sure to give it a little bit more gas and I notice the lights lit up more then I took off making sure I gave it enough gas to not die. It drove fine all the way home. Turn signal would also slow way down if I was stopped and speed up if I pushed the gas. Once I got home, I stopped to put it into reverse and I could tell it came really close to dying but managed to park it before it died. I got out and haven’t drove it since. I thought alternator problems but it’s got a fairly new alternator. Could something be messing up my alternator? I posted a previous post a while back where I had hooked up the battery backwards but I was pretty sure I had fixed everything. Any comment/help is appreciated.