What causes male to cum quick & lost erection during?

So i am a person that when i am having sex i normally takes like 2 hrs or more to cum, recently I have been having sex and I notice now that i start to pre ejaculate alot in my gf and the sensation in my penis from pre ejacualating starts to make me cum after like 15/20 min, and sometimes during sex its hard to maintain an errection to completely satisfy my gf... We tried some vitamains to boost my firtility and to give me body all the vitamins needed for my sexual reproduction but it doesn't help with my recent lost of errection problem and cummin quick... Any advise on what to do to rectify this problem?

Glow Resources

Let’s Glow

Glow is here for you on your path to pregnancy

Glow helps you navigate your fertility journey with smart tools, personalized insights, and guidance from medical experts who understand what matters most.

25+ million

Users

4.8 stars

200k+ app ratings

20+

Medical advisors