Another thing. ... playing other people's tunes us ALWAYS harder than playing your own songs. With your own material you are playing/singing what you can do. .. In your key. .. Your Own licks etc. ..
Playing covers you're playing what someone ELSE found comfortable. .. not necessarily what you find comfy.
I've done original- both my own and others original stuff- Jazz, country, funk you name it. .. And ppl who look down at those who do covers - I've found, are usually those that are jealous. Jealous that you've got a decent, often well paying gig.
I've seen these types at my gigs. .. Having a sly smirk and chuckle that they'd never 'be in a band that pandered to the seething masses' etc etc. ..
Then later, when I've asked them to fill in for an absent band member, they jump at the chance and then enjoy themselves like never before. Many saying that it was the most fun they'd had in years and that they're always keen to fill in again. ... Strange!
I, also, agree with Billy's excellent post above. Lose yr ego. . It AIN'T personal. .. Treat it ALL as a learning experience- even when playing with musos that are beginners - and apply ANY positive things you learn or have learnt. Enjoy. That's what music's about!