Your peinis size is normal.Sensitive
zone of vagina is only 2 inches in depth,Even two inch eretct penis can satisfy a woman.
Timae dependa on mood, health,your skill, and other factors.Kegel exercises are easiest and doable. search Kegel exerxises in the internet.
Search yoga site, and search for Muladhar bandh (Root Lock),Uddian Bandh, &navel Lock) and Jalandhar band,(throat lock) Maha band (all lock together..
Abdominal breathing cams the mind.