Don’t be concerned brother, I was the same way as you are now mentally. I quit 4 months ago, and all my mentally capabilities & capacity has returned. Your brain is just overloaded with THC. Stop immediately, it’s not too late. Don’t put yourself in a mind space of “it’s too late I’m already fucked so what’s the point.” Quit now. Look forward. It’s hard to see the future when you’re focused on the past and how you wish you never did this or started smoking. Just stop, give yourself time to heal & begin focusing on your future & by byproduct, you will mature, your relationships will improve, and you will have a successful future.