immigration status after separration non EU

[Alexey77]

Hi everyone,
I do apologise if this question has already been asked.

So, my partner and I have been in a civil partnership since 2014. I'm Russian citizen, my partner holds UK passport. we lived in Russia, then moved to Spain and a year ago moved to the UK. Because we lived in Spain and both had Spanish residency permit I've applied for entry clearance as a civil partner of EU citizen (not UK), received entry clearance, we moved and after 6 months of paperwork nightmare I've received a 5 year residency permit in the UK.

At the moment things are not going very well between us and there is a possibility of a separation. Therefore, I have a question. As my residency permit was based on us being partners, what will happen to my immigration status if we separate? I work full time (permanent contract 20+ grand a year), have phone contract, bank account, paying taxes, social security etc.

It was not a fake marriage or something, moving to the UK at the time of getting CP was discussed but there were no plans whatsoever.

I do like the UK and really would want to stay, especially when after over 3 years abroad getting job and settling down at my home country will be a bit complicated.

Hope you can advise me.

P.S. from what I know my employer does not support visas.