Thanks for asking your question on Healthcare Magic.
From your description, it looks like you have early ejaculation.
You need to understand that Ejaculation is a 'reflex' (which happens on optimum sexual stimulation) similar to someone touching the white part of your eye and your eyes blink as a 'reflex' response. It is one of the most common sexual problem with around 40% men suffering from it at least once in their life time.
It looks like you engage in 'quickies' during masturbation
which can become a learned behaviour. I would recommend that you train your Mind-Body to learn to get a better control over the ejaculation time. This can be done by a masturbation training exercise also called 'stop-start technique' where you recognize your 'point of no return' and stimulate your self upto that, stop and start again. Do this about 3-4 times every time you masturbate (recommended to do this as a treatment 2-3 times/week) before you then finally ejaculate. Once you have a better understanding of your 'point of no return', then use that knowledge during sexual intercourse and control the stimulation.
Alternatively, there are medicines for delaying ejaculation and also to reduce the sensation at the tip of penis such as gels and sprays for which I would suggest you see a doctor.
Good luck and let me know if I could be of any further help.