I know what it's like to have an inner voice telling you that you're not good enough. But that voice is a liar. First of all, eight years sober is a hell of an achievement, and one mistake doesn't mean you've failed, it's just a bump in the road. Don't let it defeat you.
Second, the person you liked wanted to be your friend. Friends are also precious, can you perhaps navigate your feelings to accept that friendship and support?
There's no need to feel guilty, life is hard and we all have struggles. Be kind to yourself. It's up to you if you feel like dating. I dated for six months of last year, and I didn't have any terrible experiences, I mostly made friends, but I certainly found you need to push yourself out there and accept you will meet a number of people who aren't right for you before you meet someone who is. Then I randomly met someone I was insanely compatible with. I am a very strange person, if that can happen to me, it can happen to you.....
No matter what, you matter. You are wanted. You were 'friendzoned', that means someone likes you and wants to be your friend.