Thanks for your query.Based on the facts that you have posted it appears that you have problem of Premature Ejaculation
since a long time.You have attempted many sex tricks with no result.
In majority of cases Premature ejaculation is mind related and due to performance anxiety
.Following measures will help to boost up your level of confidence and allay anxiety and there by improve your sexual performance,
1) Practice moderate exercise for 45 minutes followed by meditation
for 1/2 hour.
2) Take high protein diet rich in vitamins A,C,E,D.fruits and vegetables .
3) Avoid alcohol and smoking
4)Take some anti oxidants like Almonds 5-6 everyday.
will help you in maintaining hard erection for a long period You can certainly try it.