Ok.
So I used to have a whacking off problem. For like 2 years I beat off almos twice a day. I would try and do it as fast as possible, which might be why I have PE.

I have had many partners, and a few long term relationships.
With a few girls, I can last a long time, and other times with the same girl it is like 2 mins tops.

I never bust before penetration, and if I go slow, and stop at the right times I can last around 5-10 mins. But not usually.

Sometimes I can stop right as i am cumming but before I reach full orgasm and cum comes out but i still keep a slight erection and I can reach orgasm again within the next five mins.

What should I do? Im really busy and I dont have time to masturbate often, and my new girlfriend expects alot from me becasue the amount of partners I have had.