Why do I keep dying?

Why do you keep dying? There are two aspects that affect your survivability: health and sanity. If you waste them, you die.

Wasting Health

You waste health if you:

• Fight without armor. Log suit protects you from 80% of incoming damage.
• Attack a spider on webbing near a 2 tier nest or that nest itself it it has spiders - jumping spiders will emerge and attack you. There is no reason to do this.
• Do not kill hounds ASAP - in packs, they are harder to kill, but they appear one after another - exploit it. Also they can be stunlocked, so if you fight them 1x1, you will take less damage.
• Tank a Treeguard. Don't do this. Land three hits, dodge its attack and repeat. You both should fight him because he has more health in DST. Or plant pine cones.
• Eat monster meat or red shrooms.
• Tank a big wave of spiders. Kite them with 2 hits, kill with traps or escape.
• Directly attack a frog during frog rain. Use traps instead.

Wasting Sanity

You waste sanity if you:

• Are exposed to rain. If spring is your starting season, make a Straw hat and a Pretty Parasol ASAP. Trees also provide some protection.
• Are close to monsters for a long time. Almost every monster has an insanity aura, and hounds are not an exception. It's recommended either kill them quickly or escape battle if possible.
• Eat raw green shrooms. They decrease sanity, cooked ones increase.
• Eat raw meat or monster meat.

Recovery

Health is recovered in small amounts when you eat food, but don't eat monster meat and red shrooms. Also you can recover health by using spider glands and eating raw blue mushrooms that can be harvested at night.

Sanity is easily recovered by eating cooked green mushrooms. Also, sanity is restored when you invent something (craft a thing the first time).

Build a crock pot and drying racks. Crock pot foods and jerky are more effective for restoring health and sanity.

Yes, you are essentially expected to die over and over (and over). That's just the sort of game this is.

In the original DS, death was mostly permanent. You could use a touchstone once if you found one, and you could build meat effigies eventually, but otherwise one death was it. Mechanically, that meant that those of us who learned on DS started over a lot, rather than attempted to recover from our early disasters. We took what we learned from the last "run" and applied it to getting further next time.

If you decide to keep trying to learn the game, I would recommend turning respawning off for a while, until you have a good grounding in the basics. If starting over again and again is a deal breaker, this might not be the game for you*. That said, there are probably mods that would let you mitigate or eliminate the resurrection penalty, but I am not familar enough with them to recommend any.

*_{I understand that statement could be interpreted as elitist; that is not my intention. There is absolutely nothing wrong with not liking this style of game, nor should someone subject themselves to something they find unpleasant to appease internet tough guys, and the sunk-cost fallacy is aptly named.}