Playback live.... oh no!

Allright, it's going better than planned. I will and nobody can stop me sit every day now until 2h in the morning to mix my songs.

Oh, I didn't explain that yet: It's quite complicated to perform as a solo artist. At least, I imagine so.
First of all, all eyes are on you and it is probably easy to be scared shitless.
Secondly, if you heard my songs - some of theme are quite heavy on... well.. more than one voice ;)= so I need playback:

LIVE:
* Voice
* Acc. Guitar

PLAYBACK:
* Background Vocals
* Addl. Instruments etc.

But not just simple playback that can be played from a mp3 player.
Since there are usually no beats to hang on to I'll need to have the whole song in my ear. By that I mean: What if I play just guitar and sing to that - and after 43 secs I'll have a chorus. Ok, I could do that with a simple metronome in my ear. But if I miss just ONE beat, the chorus will be on the wrong spot and I don't need that.

Hey, thanks for listening. It's always better to write this stuff down, maybe I find something with optimizing potential.