Does supply get better?

I’m four years into my teaching career, and working on supply (in my area, jobs in my subject come up VERY rarely - 2 perm posts in the last 3 months within 30 miles of me). Have resigned myself to doing supply and whilst I don’t mind a lot of it (leaving on time, no planning, no paperwork, no follow-up behaviour stuff) my GOD is it demoralising.

I feel like I’m going in every day, fighting fires and being the phone police, getting ignored/eye-rolled at/straight up insulted by the kids, sitting alone at lunch/breaks because all the other staff go to their staff bases instead of the central staffroom, and then going home. Calling for SLT feels even less worth it than ignoring any issues as there’s a back and forth of “I’m not leaving/you’re not my real teacher/it doesn’t matter what you say cos you’ll not be here next week” for ages before they leave the room, SLT takes twenty minutes to arrive, and the kids then stand in the corridor disturbing everyone else.

It feels like there are days when the balance of things said to me by kids is so negative - and I’m not usually one to let that affect me, but when there’s no counterbalance of nice moments with students/commiserating with other teachers I just feel so rubbish. The idea of going back into a temp contract also fills me with dread, as all of the ones advertised conveniently stop right before summer (lol). I know I’m a good teacher, but it just makes me feel rubbish. So please - does supply get better? Like at all?