Personally mate, I would leave. Spend your time doing/playing something more productive I was sans band for about 6 months last year after being in a situation similar to yours. I found that just being in the band put me in the frame of mind where playing bass was a ball ache, and something i HAD to do rather than something i wanted to do. Also paying studio rental every month just to keep re-learning 'new versions' of the same bloody songs over and over, and barely getting any gigs was just a waste of time and money!
After I left, I actually stopped playing altogether for about a month, but when i went back to the bass it became fun all over again! I didn't bother looking for a new band as I felt I didn't really need to be in one at the time. It was only when I noticed that a friend of mine's band had just lost their bassist that I thought about it, and discovered I was ready again. My love affair with the bass has been getting saucier ever since
Something will come along eventually, us bass players are a rare breed!