I'm rarely aroused sexually. Help.

I'm a 26 year old man, otherwise pretty healthy and in good shape. I regularly exercise. I eat healthy. I meditate. But I'm almost never sexually aroused. I remember my teenage years when I would be sexually excited/aroused beyond control. But I kind of went under depression in my 20th year and things started to fall apart from there. I completely forgot about sex and I didn't want to have it either. That must have lasted two years. But since then, no matter how much I want it, I can't get sexually excited. I have to work to get and maintain an erection i.e. I have to use my hands to stimulate it. I've stopped having erections without assistance and I never feel really horny. I've since been caught in situations where girls after making out with me want to perform oral or vaginal sex and I just can't get it up. Truth be told, I'm not sexually excited at those moments at all. At first I thought this problem will sort itself out but now I'm worried. I think I should seek medical help.