Early Ejaculation, Especially In Missionary Position, Partner Does Not Get Orgasm, Erectile Dysfunction, Worried About Difficulty In Not Satisfying Partner. Tips For Better Sex?

I am from south Tamil Nadu not near by Chennai even, married and having 2 kids. We are leading a successful married life so for with out any problem. We are having a very good understanding.. I am more interested in sex than her. I am noticed a prob. with me recently that i could not long lang last even 2 min while having sex with my wife. I used to have a foreplay for 10 min we enjoy in that moment... when i started pumping slowly i can t even with stand more than a min..Ejaculation is very earlier when i am pumping hard / my wife is pumping hard. less than even a min sometime during my first shot..When i am on her top ejaculation is much faster..during missionerry position i hv to rest my whole body weight in my hands and pumping veyr hard in to her which my wife loves a lot...i cant even with stand a min. which i am very much sad abt. this... Some times my wife have shared with me that she has not got her orgasm .....My wife is everything to me i want to satisfy her the most...I want to have better sex with her... Pl. help me to get rid out of these as I am very much worried abt. this... My wife is not too much worried abt. this..but i want to satisfy to the most...means she have not got the female ejaculation yet. We both are having very good relationship and good sex life too. i need to have erect penis which can with stand up to 5 min atleast..My age is 39 and my wife is 35. My penis size at erection is 4-5 inches max ... Hv heard that pils( viagra ) can solve this prob.which gives more strength and stamina for longer sex...whether this is correct or any other natural method or theraphy i should follow to have longer erect penis.. i want your advice to have a better sex with my partner... Pl. guide /advice..