@23 still a virgin, with depressing past experience

Hi guys! need help! Just wana share my xperience, had a girlfriend for4 yrs but never had sex wd her, only foreplays and smoochin. I try to honor marriage before sex. But one day we took a bath together, naked, NAKED. But to my surprise, i did not acquire an erection. I was so worried that i became very depressed. We tried to have oral sex, she attempted to give me a ******** but again my 'junior' did not cooperate. That experience tormented me until now. I am a seafarer and i dont have someone to share it with, during our time in brazil, we went to a bar, my senior officer forced me with a girl though im not that sexually aroused. I took the girl,but to my disappointment it happened again. She even gave me a ******** but still nothing happened. I am so depressed. I have this strange feeling that nothing arouses me anymore. I dont want to be like this. I dont have the mood to masturbate anymore. When i was a teen even just a peek from a girls bra could get me hard rock. But now i am having difficulties. I try to console myself but my thoughts keep drowning me. I feel like im losing confidence in myself. is there any way i can regain my arousal and sexual urges? Please do help. I want to be happy again, i want to be with the girl i love but having this erectile problems really gets me down. I am a seafarer and i dont have anyone to talk to about this issue. Can there still be hope? I cant afford any therapists. Help guys.