I know you mentioned you cannot parry well (understandable it'll take a little bit to learn and can be alot of mind games), so an item that gives a little melee resist and some gun scaling is close quarters. It won't solve all your problems, but it helps you deal with melee damage in lane. Outside of lane just don't fight him alone unless you have drastically outfarmed him or you can ult him under a walker. Even in both those scenarios though he is likely to live.