So an update...
I went back to shop and spoke to manager, on Monday after work, once I'd calmed my OCD enough to do so, I apologised and explained what had happened, the staff were lovely, very understanding and accepted my apology for their gate attacking my car (the gate was uninjured and had no personal insurance so its not going to be paying for the repairs itself...) The manager wasn't worried about it as others have knocked the gate off entirely before, so someone bumping it and causing absolutely no damage was of course no issue... Which was a huge relief... One thing dealt with...
Then had a very long conversation at the doctors where I explained and demonstrated my obsessive tendencies and communicated that I felt counselling may be a good idea, since I was struggling with all the "lovely experiences" that had triggered my OCD in the last couple of years and more importantly, recently.. The person I spoke to took loads of time with me and gave me contact details of counselling services to refer myself to. Which I've done. So now I'm booked for an assessment phone call in the next few weeks.
I declined medication for now, though I was assured I could have it if I came back and wished to use it. They recommended I keep exercising like I recently started to do again, keep doing my hobbies and give myself time for me. I would be doing that this evening but I've got a lot of work I need to get done soon, so currently not hobbying like I'd like to... Though I am aiming to spend most of Saturday doing my own thing if I can.
Had a conversation with a good friend about everything that evening and that helped also.
So I guess I'm making positive and logical steps towards taking back control...