The Black Forest will quickly become trivial. No, really. You'll get better, and your gear will get better, and eventually you'll be able to run into the Black Forest with nothing but a shield, a club, and a pair of pants and absolutely wreck everything.

You can't do that yet because there's a learning curve and it really starts to kick in as soon as you move to new biomes. It seem extra steep if you're not geared up or you've not yet developed enough knowledge and/or skill (player skill - not character skill). Once you do it'll be much, much easier.

My advice is the same as what others have said. Get good at parrying. Practice on the weaker enemies until you get the timing. That lets you counter attack with bonus damage if you swing fast enough after you parry. Depending on your weapon you might be able to hit the enemy twice and get the bonus damage before they're no longer staggered.

Practice stamina management, get used to running/walking away from enemies. Often you can walk fast enough to get away without burning stamina. Get good at dodging and know when to run away from a fight that you probably can't win. Use terrain to your advantage if you can.

Carry a bow and basic arrows for range combat with some fire arrows for tougher enemies. The bow is a great way to start a fight, sometimes you can one-shot certain enemies with it while sneaking due to the bonus "backstab" damage you'll get if they're unaware of you, and is also useful for hunting deer. A parrying shield (the round ones can parry, the bigger ones only block damage) paired with a decent one handed weapon seemed to work really well for me throughout the game. That bonus damage when you stagger an enemy makes a big difference and you'll start dropping enemies in just a few hits once you get used to it.

I stuck with the leather armour set, then upgraded to troll leather, until I got to the point where I was mining silver so you don't need to grind bronze armour or even iron unless you want to. Bronze will make your life a bit easier but the troll armour is only 2 armour points lower per piece, 6 base versus 8 base for bronze, so it'll work and it doesn't slow you down like bronze does. I didn't want to mine enough bronze to make, and upgrade, a full set on my first character and it turns out that you really don't have to. You probably should, but it's not necessary.

Honestly armour was secondary to having a good shield and knowing how to use it, though good armour means if you miss a block or parry and take a hit you probably won't die, or nearly die, in just one hit from stronger enemies. I found a slightly upgraded club was just fine in the Black Forest, and even used it in the swamp for a while, but the mace (bronze or iron) was even better. Some enemies have weaknesses to certain types of damage, but may also resist other types. If you're hitting most enemies for a good amount of damage, then hit something else and it seems like you're doing a lot less - you've probably just found an enemy that's resistant to that type of damage. That's part of the reason I always run around with a bow with both regular and fire arrows and a mace. Gives me piercing, blunt, and fire (dot) to work with. It's rare that something's resistant to all three.

Good luck in the forest! Hopefully some of the tips in this thread help.