You can get married while in the UK. You and your partner will have to give 28 days notice to an HO approved registry. They then inform ho and the notice period could be extended to 70 days to investigate and/or interview each of you separately before permission to marry is granted
Hopefully you have sufficient time left on your visa to accommodate this, marry and switch to a spouse visa within the uk, assuming you meet the requirment s.
Char (CR001 not Casa)
In life you cannot press the Backspace button!!
Please DO NOT send me a PM for immigration advice. I reserve the right to ignore the PM and not respond.