If you really wanted to die you wouldn't care what anyone thought. I'm not saying you don't feel absolutely horrible. I'm saying you sound like you actually do want to be talked out of it.
I personally don't like throwing words like coward at suicidal people, who already feel rotten enough. I also don't like the old 'so you think you have it bad' routine either. Plus I don't think suicide per se is cowardly.
In fact, I think if other people weren't so condemning, some of the grief, loneliness, and guilt would lift, and in a ironic twist, suicidal people would feel better about themselves. Not having to sneak around furtively takes a bit of the awfulness away.
Liam, I think a key remark you made is that you have alienated your friends because you are ashamed. If a friend can't take you in the state you are in, then what kind of a friend is he? Or better put, why can't you let your friends take you as you are, which they very well might be wanting to do? You don't have to tell your tales of woe for hours on end, but they can drag you around to their houses and places they go to, not trying to cheer you up, just sort of gathering you in. Ask them to.