750 ml of wine at 12% = 9 units per night. 9 * 5 = 45 units per week.
That's considerably more than the guidelines.
With excess drinking we tend to talk about problem drinking (drinking a bit too much); harmful drinking (drinking enough to cause harm, and you're certainly doing that) and dependent drinking (drinking enough to have a physical addiction).
It can be dangerous to -without supervision- stop drinking if you have a physical dependency.
Here's what you should expect from English treatment for alcohol misuse: https://www.nice.org.uk/guidance/cg115
Here's an interactive flowchart: https://pathways.nice.org.uk/pathways/alcohol-use-disorders/...
You need, and deserve, medical advice. Please go see a real professional.