Looking for a better sex life

Patient: I am 54 years male. I have lot of sex drive and need. I cannot perform well as I do not get an erect penis. I do take 1 tablet of Vigormax couple of hours before intercourse, but it does not help.Is this Vigormax any good, does it has any side effect? If its good, should I take more than 1 tablet regularly or just the day of the intercourse.?Please help.