Donut ( big foreskin )

I’ve been pumping for 1.5 months 4-5 days a week with litle to no results.

I now do 3 x 10 mins or 1x15 + 1x10 at 4-5hg

I always get a donut after pumping , is it a sign of overdoing it ?

I started slowly at 3-4hg sets of 5 then 10 then sometimes 15.

How can I prevent donuts?

As far as I know, you can prevent this donut crap by staying hard in the tube. If you feel yourself losing your hardness in the tube, take it off and jelq it [or watch better porn he he he] and then back in you go!

Oh yeah and rest.