Greetings. Are you married or sexually active? Is this a recent onset issue ? Firstly, do not worry about the length of your penis. You seem to have a reasonable penile length that is needed for normal pleasurable intercourse. Do not get carried away or depressed by what you see in videos / read online / or about length increasing pills. Also for difficulty in erection, the commonest cause is anxiety. So see a qualified doctor - sexologist / andrologist near you. Warm regards .