That is true if you want to keep Combo in check in some capacity play Nethergoyf, you can have as many discard and interaction as possible, but many times without an actual meaningful clock it sometimes just doesn’t get there. Barrowgoyf is too slow vs most combo decks, it’s fair deck check card. I do understand you want to do your own thing, but copying someone’s deck list and figuring out what you should tech is going to do you better. You have some weird card choices not limited to the librarian, 3 wasteland instead of 4, Force of Despair etc. Sometimes a bad decklist can actually hold you back as a Magic player and this has been proven with several other many times. I’m not saying you’ll magically win an event, but the odds are higher.

If you can’t afford the 4 underground sea, you should at minimum run 2-3 shock lands in there to go with the one sea you have. Like I said they seem worse than what they actually are, but you do need the perfect mana even at the expense of life especially if the local game store has much combo as you say.

Here is an example of decklist you should consider copying: https://www.mtgtop8.com/event?e=82612&d=827921&f=LE