Recently become depressed after my tinnitus increased a month ago l. This caused my ocd to get worse and sleep to get worse. 
and taking valium to help sleep at time. 

I've told my employer all of this this.

Knock on wood my tinnitus has gotten quieter again but on top of this I'm very bored with my job..

I basically go into work and play on my phone  all night waiting to go home.

We are very short staffed now, I'm contracted part time but have helped them out for months doing extra hours. Yet they've put me on more hours this month. I didn't complain but I edited the rota and sent it back saying that all I can do.. (only a few hours knocked off the extra shifts they put me on).

This wasn't good enough.. The boss basically said that I'm not being a team player lol.. At that point I've lost all interest in staying here and am being forced to work extra hours on top of the extra I agreed to.

I have £5k+ in bank and if I'm honest couomd find a job within 2 weeks.. 

But I'm. Still worried about leaving woth a job lined up yet the notice I have to give is 4 weeks so I'm very close to just handing my notice in and getting any part time job in the mean time.

What do you think?