Anybody know what could help my knee?

A few weeks ago I fell and dislocated it, the hospital put a brace as such on (you can see it in some pics). I got the all clear yesterday and was allowed to take it off - now all of a sudden I've got a huge nagging pain in my knee & it aches. I can walk but it absolutely kills. I phoned 111 & they told me to keep it elevated but it just makes it worse ☹️

I know it's probably where the support has come off but it kills 😣😣