Newbie has a few questions

Hey guys my name's Andy. I have a few questions I was hoping to get advice. For ever since I got circumcised ( 4 years ago) I noticed that my penis was getting less and less sensitive, and in the past year I've had sexual encounters where I could get erect but would go soft a minute later as soon as it was my turn to receive. I've recently quit watching porn and masturbating ( 3 weeks now) and honestly I feel like I could keep going for alot longer. But I've started dating and want to get this under control so my questions......... 1 do I just have to complete stop anything sexual until my brain recovers 2 if I buy a Fleshlight and masturbate once a week would that actually help with the loss of sensation as it mimics a vagina and 3 I've read about " cock rings" helping maintain erections is that something I can try in the meantime? Thanks alot in advance guys and sorry for the essay