Can't satisfy my lady

ill make this as quick as I can so not to bore you too much . Basically I've been with my partner for nearly two years now and we've never had proper sex , This is my fault mostly. I have trouble keeping erections (tried viagra etc and many other medications )but nothing helps. I've had a life of depression and anxiety and I'm in the process of trying some psychological help but I'm mworried. The woman I'm with has a very high sex drive and I feel I'm just disappointing her to the point where She will cheat on me . I'm in contact with my doctors now about the whole situation , which to me is a massive step , but I don't know how long this process will take . It's got to the point now where I even avoid trying to imitate sex as I know it will only lead to disappointment . I feel like leaving her now as she makes these little comments here and there about it all , the one the other day was "I'm wasted on you " . I understand her frustration , but it knocked me down so bad . I don't even know why I'm struggling with erections. It was bad 2 weeks ago as I ended up in hospital having taken a really bad cocktail of drugs ... Yeah I know , childish and stupid but I felt so low about things I felt I couldn't go on . I want my Mrs to have a decent life (sex life included ) but I'm starting to feel I'm not the one that can do this. Should I leave her and stop destroying her happiness .