Q: Car stalls sometimes at lights or stops, trouble starting it sometimes after adding gas.

My r53 mini sometimes stalls at lights or stops, I experience the rpm dipping down sometimes then it'll go back to normal. If it is going to stall the rpms will dip a bit then fully dip to 0 completely shutting off car. I crank the car and it turns back on like a second or two later. I also experience an issue where if I stop to get gas after I add gas to my vehicle (car is off) when I try to crank it, it'll crank but fail seconds after best way to successfully crank it is to apply some gas as I'm cranking and continue to tap on the gas for a few seconds to get a successful start up. Also smells like gas when I start too as if gas fumes are coming out of exhaust.. and the check gas cap light comes on but my gas cap is secured. Please help me identify my issue, I believe it is the fuel injectors but that's just a guess.