First of all, size of the penis is genetically determined & it does not increase after a certain limit.
Regarding the problem of premature ejaculation
, it's mostly related to anxiety
So...don't worry about all this & stay relaxed
Avoid stress...practice meditation
..this helps in improving concentration & builds up the confidence level.
Performance can be improved by having a diet rich in fruits, vegetables, fish, nuts & honey
Avoid smoking & alcohol.
Despite these measures, if you experience difficulty, it will be better to rule out other causes like high blood pressure
, blood sugar and other local causes that impair blood flow to your genital organ.
One more thing...avoid consuming any over the counter medication
which claim to increase the size of penis or improve performance...it may be harmful.
Wishing you a Healthy Life.