Help with Premature ejaculation 17 years old

Patient: 17 years old, just started my sex life and i ‘ve got PE.i don’t last even 2 minutes…when i do it myself…i feel i can last…but when it’s with my gf …i think it’s out of my control…for a few times…i could last up to several minutes(around 5) but we’ve made a pause of 3 weeks..and i’ve been to gym ….and i think it might the problem …i don’t know what to is affecting my self’s loooowwwplease help me. WHAT CAN I DO TO STOP IT?

Symptoms: -PE
-i went to gym
-i have low self esteem