Whether PR is the answer I don't know it needs looking at along with a lot of things. Personally I think one of the big issues is we no longer have conviction politicans they are career politicans they go straight from university to one of the political parties with no life experience. Most people would be shocked how naive and stupid are some of our politicans who wield extreme power and would be unemployable in any other walk of life. The reason most of them like the EU is it's a source of employment for them and a very very lucrative one at that.
I would agree that for most a career in politics is just that and it is no longer a calling. Just last week we witnessed Ian Paisley admit in parliament that he had accepted free luxury family holidays in Sri Lanka. In return Ian wrote to David Cameron to lobby against supporting a UN resolution on Human Rights abuses in Sri Lanka. Despite the fact that he was caught red handed and given an unprecedented ban Paisley still hasn't resigned. Arrogance on this scale is breathtaking, but of course Ian is by no means an exception.
If PR achieved nothing else it may end the status quo, which clearly isn't serving the electorate well. I may not agree with you on Brexit Stan, but I understand entirely your frustration at your parliament ignoring the democratic voice of the people who put them there in the first place.
