Austin Hardman

I keep having this issue, I hook into a decent sized catfish and I've been using 15lb braid in one of my reels and 20lb braid on a baitcaster and when I hook up I fight the fish my drag is set up and everything for it but when I get the fish a few feet from shore the line snaps a few inches below my wieghts and I dont know what the deel is I've tried holding my rod lower so I dont have as much tension on it but it keeps breaking and i recently set my baitcaster up with 30lb braid and i havent caught a fish on it yet with that line and I'm wanting to see how that does, any tips or advice i should try while I'm hooked up to see if it doesnt snap?