I’m no expert, but inner ear infections and damage as a result of inner ear infections can cause symptoms of dizziness and tinnitus. My mum suffered from this for over a year when she got older and she’d have to go and lie down because it was so intense. Maybe getting checked out by an ear, nose and throat medic for signs of damage/ongoing inflammation-infection?
Wishing you guys well.
All started after a week with a horrible cough / cold.
I have been 3 times already in the GP and the answer is always the same, it is a virus, it will pass.
it is getting better slowly, slowly but it is mental, 3 days OK then 2 bad, then good again
That’s what the GP kept saying to my mum too. If you were able to see an ENT specialist, they might be able to help identify whether the virus has caused evident physical trauma to your ear that triggers the tinnitus. Or maybe if they see signs of ongoing infection such as inflammation then they could think of prescribing anti-inflammatatories to counter the problem. But I know the wait list for specialists is insane in the UK. 
Sorry to read that, you have my full empathy. Severe ear trouble or tinnitus is an absolutely horrible and a mentally draining condition. My gf strangely enough ended up having it during the pandemic and sadly something now she has to manage and live with.
I myself had the most odd ear infection with what was an 8-10 week viral sinus infection before Christmas. Definitely all linked and multiple doctor visits, try this, take that it drove me insane! I never get ear infections but this was bad, my left ear was hurting so bad stabbing pains etc and constantly blocked no matter what I tried it kept getting worse. Eventually it did pass in the new year thank god!