Young wish erectile dysfunction

Patient: Iam a 25 year old male and iam 6ft5 334 pounds, and i have a issue with erectile dysfunction. The issue is when i watch porn movies, i dont have a issue with getting hard, but when i actually have a person with me, its kind of difficult for me to get hard. Im thinking iam a young, why do have this problem.keep in mind when i was like 18 19 i would get extremely hard all the time but now its like when i watch porn i can but with someone i cant.Also i suffer from depression, i have been for some 4 years now, does that have something to do with it.Also what are some things that i can do in order to get hard and stay hard.Will taking testerone help.I have a freind that tells me that naturally he can stay hard after ejaculation, but when i ejaculate, i get soft.Thanks for your help