At first, yes, it would seem the entire swamp wants to come say hello.

-Just work the periphery until that first wave is defeated. Don't push in too far at first.
-Use blunt weapons; they seem to well against everything.
-Score the ingredients for sausage to upgrade your food selection.
-Use the hoe to raise land out of the puddles where leeches roam. This will help you get out of the swamp faster and safer as you push in further. It also restricts leech mobility and lets you engage them on your own terms. You don't want to be stuck in deep water for long.
-Use torches to help you keep your bearings as you push deeper so you don't get turned around when stressful situations occur.
-Use workstations to suppress enemies from spawning near the paths you make.
-Use fire and slashing weapons against abomination. Drop campfires at its feet. Later, you can lead it over fire geysers to keep it lit.
-Keep your poison resist up always. Don't let it wear off for too long.
-Watch out for those areas where draugrs and skeletons have spawn points. Steer clear of those for now.

As you gain more experience around the edges of a swamp, you'll gain the knowledge and confidence to handle it better. Once you're able to get better weapons, armor, and food that the swamp provides, the challenge the swamp presents will become several orders of difficulty easier.

Just be smart about not lingering too long in the swamp early on. Each time you get in and out alive will better prepare you to stay longer the next time. Enjoy the challenge the game is presenting you that is the swamps. You'll be patting yourself on the back once you master this area.