I have pre mature ejaculation in 1 min i cum.how to stop it?or improve it?

Help is available: Premature ejaculation (p.E.) is treatable with medication. Part of the problem is psychological, so relaxing one's sexual intensity (and thinking about other things for a few moments) may help. Part of the problem is physical, so using two condoms can decrease one's sensation and hopefully last longer before orgasm. One's primary care doctor or a urologist should have additional ideas.

SSRIs: There are some prescription medicines that may help. Among them the antidepressants ssri that as a side effect delay ejaculation. In the past drs prescribed melleril. There are technics like the "stop & go" or to pinch, press or thight the penis when excitement is too much (8/10 hardening) at the base if inserted already, or at the crown of glande if still out. Attempt to satisfy your woman first.