Braid for the mainline was the title and it sounds like no thickness of braid will sort your issues,it will just tether fish totally.First you need to lead the snag to understand what you have got out there,no terminal tackle,just a lead,if you lose the lead then its probably impossible to fish,with the fishes welfare being the issue.You might find an area that can be fished without too much problems,even if you have to upstream to the spot.Next tackle,no matter how heavy your line is if your rod is too soft,or you do not give it some, then you are wasting your time.A harrison chimera floodwater,nash fang gaper DS hook, big centre pin with 12lb minimum line and plastecene for the weight will give you a chance.You need to hold the rod and you will need to hit the bite as soon as possible.For the next 2 or 3 seconds you need to wind that pin,and give nothing,even if the rod is in a c ,then you can usually play them in the open.This is a brutal method and as other people say think of the fish and what you are doing to them.Lastly i do not fish like this normally ,but sometimes have done so in the past in tight swims.