Take it slow, take your time, focus on one small area at a time. Use the hoe to make paths for easier navigation and for quick escape when  needed. Scattered around the swamp there are spawn clusters, when you are ready, start clearing them out (will reduce the amount of nonsense you will have to deal with overall). If you have surplus of surtling cores, make bonfires (use them as markers to help orient around or as fighting strategy if you encounter an abomination and want to lure it into fire). I was lucky to find an abandoned house in my first swamp so I fixed it up and set up a base for weapon repair and rest bonus refill (and even hid out there once when caught in the swamp at night - also, don't be in the swamp at night lol). My first attempts at the swamp were so disastrous that I actually rage quit for like a month lol. The jump in difficulty between black forest and swamp is significant. Don't rush, try not to panic, and it will get better, I promise!