What Causes Small Penis With Erectile Dysfunction?

hi doctor i m 32 year male, i have basicaly 2 sex problem....1 i hav small penis (3 inch normlly and 4-6 inch errect) and i hav errection problem so i cant enjoy sex 2. i like man for sex , i wann to know gayism is physical problem or phscological problem mean it related to only thinking or it is narlaly phenomina...pls help me due to those problem my marrige has broken...i want my life settle now...