Don't get circumcised. Keep it natural. It won't make a difference in how long you last and you'll have lost your foreskin for nothing. That'd be really, really sad. :(
Have you tried using thicker condoms or numbing with cream? I also know of people that use breathing of meditation techniques for this. I'm no expert in the situation, but asking before you need to go through the knife.
I would also suggest you to go to a psychologist specialised in sex (a.k.a. sexologist), if you haven't tried yet. What you are saying is a very common thing, and medicine has been working on this for years. We don't have the final solution for it, but we do have many work arounds and if it's something that is altering your life, you should try to fix it.
My advices are going to be more sex-bro kind of thing. A trained physician or doctor will have better answers than me.