Is a personal loan my best bet?

So for context I have fair credit at the moment.

I hold two credit cards with NatWest

I tried another credit card balance transfer with Barclays but they wanted payslips that I don’t get. I work for cash but get a P45. So I closed the account.
I tried recently for a credit card and was accepted by capital one but even though I stated I need a balance transfer it’s showing only £200 limit, do I need to wait for the card to then apply for the balance transfer?

I also have a newly opened nationwide account that I could possibly get a personal loan from. It would be paid back every month for about £100 but could consolidate the debt to one payment.

I could pay the loan monthly then at the end of the year when I’m expecting to get some money I could pay some back early. Would that affect my credit score?

Is my only option to get a personal loan? Or am I missing anything else?