Too long to achieve orgasm

[Maskedbandit]

I have had this problem for a number of years. I have no problem getting an erection and can maintain it for a long time; however I can sometimes not orgasm for around 2 and sometimes 3 hours, which obviously is exhausting and at times painful. I have had a long standing pituitary gland problem (too much prolactin) that has been managed by medication for over around 6 years. I have had blood tests (though not for about 2 years) that have indicated normal hormone levels. I am due for an appointment (end of December) to have this overall condition reviewed, but now have an active sex life so would like to get the full experience. Are there reasons why I am not able to cum quicker or any tips out there for finishing quicker? Would something like Viagra help?

Thanks in advance