here is a small sample of my writing... it isn't shit, though it is often treated as such by band members or venue owners...

Maybe your band members and venue owners are more objective judges of your writing than you are. From what I've gathered from 20 years of playing in bands is that if my mates do not believe in the strength of the songs, the audience sure won't.

Something else I've gathered is that venue owners come to know what works in their venue. If it's a bar, the objective is to sell drinks and they want music that people will want to drink to. If it's a coffeehouse or concert, they want headliners who will bring in the audience and support artists who will hold the audience's attention and suitably prepare the crowd for the headliner. If you're not up to those tasks, then you're of little use to the venue owner.