Best plan for a fourth year uni student?

I'm crashing out over my bad spending habits lol.

For context, I (20,M) go to uni three days a week and have done for three years. As it's a Scottish uni I get SAAS funding and got £9,400 for years 2 and 3. I was applying for fourth year when I realised I've got horrendous spending habits. This needs to change so I'm posting here for help.

I work 10.5 hours a week and get ~£155 a week. So tell me I'm now only sitting with 6 and a half grand?? I've blown through so much money travelling (I'm a commuter student), paying dig money, partying (once every month, if that), fuel for car and on stupid subscriptions like YouTube Premium.

Rant over lol.

Are there any investments/ISAs/similar help schemes I can take advantage of as a student in my final year?