There are a number of reasons as to why you weren't catching so go easy on yourself.
I recall fishing with my best mate Paul and a few others down the pump dock. The channel that joins the 2 docks together was amazing for eels. It sad around the time that the white boat "Sarsia" was afloat.
Well, we used to bait up our rods and cast out then go and have a game of manhunt on the boat. This one time we were on the boat I saw my rod slowly being dragged towards the edge and almost in, the rod I ha at the time was an old boat rod coupled with an old red Daiwa Millionaire. I legged it off the boat and grabbed the rod, struck into it and it was solid like it was snagged. All of a sudden the "snag" started to pull back but slowly move up against the flow, it wa a fish without question. It even put a decent bend in this 30lb class boat rod. I played it for around a minute before I lost it. On bringing the rig back in and composing myself, I looked at the hook length and it had definitely been bitten through. To this day we can only assume as to what it was but if love to of got it in 🐋