When the ejaculation occurs within one minute of beginning of the inter course is considered to be premature ejaculation
. Your's being 1-1.5 minutes doesn't qualify as premature ejaculation.
90 %cases of premature ejaculation in our country are due to faulty practice or over expectations or ignorance and can be relieved just by understanding the physiology and anatomy of human sexual organs.
Increasing the frequency of sexual inter course or increasing the frequency of masturbation to 6-7 times a week usually helps. To the extent that you won't require any medications.
Try this for 2 weeks and you can contact me again after 15 days if the problem persists.