Assaulted and not sure the best way to proceed

[Guest]

I was assaulted on the London underground four weeks ago by someone I know who I have been in dispute with over a business matter going back over two years...the matter went to court and they did not win...he then launched a defamation campaign contacting people I know and telling untruths as well as sending me foul emails...I told him I would have no contact with him other than through legal channels and I had no contact since end of 2019...I was sitting down on the tube and he appeared above me and as I looked up he sucker punched me in the eye and continued to punch and kick until he was dragged off me and ejected from the tube...he shouted "your dead" a number of times...apart from the CCTV in the tube a witness filmed the assault and I reported I Lt to station staff and have the train details...after the attack I spent two days in bed then noticed floaters and flashes in my eye...I went to an optician who referred me urgently to Moorfields eye hospital where I had emergency sight saving surgery on a detached and torn retina from which I am recovering but will be out of action for at least two weeks more...I have not reported to the police mainly because I have been very poorly and the man in question is very volatile and I want to wait till I am fit and healthy before going through the strain of legal proceedings..on top of this the current situation means that im not sure how this would be dealt with as other more important Covid-19 things are dealt with...could you advise on the likely outcome and process?