I've had two serious attempts worth mentioning, both partial hanging. The first time I failed completely, was sober and my heart wasn't in it so I just went to sleep and forgot about it. The second time I got emotional after drinking to combat my SI and sent goodbye texts to friends and family moments before trying to hang myself. It didn't work because I was too drunk to fasten the knot on my carotid artery and I ended up failing and just getting the extreme pain and exploding head feeling, I ended up on my feet, blacked out, and just went to sleep. Woke up to police asking what I had taken, blah blah blah and what little family I have left outside the apartment. Spent five days in the psych ward convincing them I was a rehabilitated "sane" person and got out on New Year's Eve. That was a little over two years ago now and I've spent the entire time giving life another chance and trying to see if I couldn't give it another shot. The answer was no. I'm jumping to the most extreme method I can think of within the next two days and I know my heart is in it.
My advice is if you don't think you're ready, maybe shelve the idea until you are. Is being afraid that you won't try again really that bad? It sounds to me like you still have some hope, somewhere. Even if it's small, I think it's worth hanging on to. I feel like breathing your last while thinking that you regret the decision isn't worth it.