Job I hate

[dontbesillyhenry]

I really cannot stand it. The targets the pettiness the constant blame culture. This is my second job and initially was taken on as having to do a certain amount of hours, I've found this unsustainable due to working full time and I've had a lot of family issues poorly relatives etc so told my boss I wanted to leave. They then offered me a bank contact where I could choose my hours but now are saying I can't start until a certain date yet I just cannot sustain working these hours. The notice period is 3 months and I just cannot sustain working these hours with family life.
Can I just leave with no notice?

Yes of course you can. The firm may not give you a reference though. I wouldn't worry about that, there are ways round it.

Find another job that suits you.

If your contractual notice period is 3 months then it isn't a good idea just to walk out leaving them in the lurch. How are you going to manage money-wise if you suddenly go to zero income overnight.

Think through your options carefully before making a rash decision.

It sounds like your management are being supportive and meeting you half way, re your hours, why don't you have a reasonable conversation with them and work it out so you can transition towards the bank approach if you're struggling.

This is a second job so the money isn't an issue really. I don't want to leave anyone in the lurch but I really can't bear it it's making me feel sick

You can give notice and get signed off sick for the remaining time. Nothing illegal in that.