Where to go from here? Newbie ponderings

So, yeah hi. I'm new here.

When I first started out I wanted to make a hack and slash uber-tank because I often like playing tanks in games and outlasting the opposition while methodically grinding it to dust. It looked like Templar was the best chance of doing that, so I started a Templar and picked up a sword and shield. That lasted all of 10 levels before I got a Summon Zombie skill gem and a Firestorm skill gem, and realized that the game was infinitely easier as a necromancer/spellcaster. So I started over as a Witch.

The other day I finished the campaign on normal difficulty level. I was able to roll over almost everything in my path with my horde of minions and spell casting fire support, though toward the end there were a few bosses and a few enemy types that pretty much forced me to employ "cheap" tactics. It seemed like the difficulty level of the game was starting to go into a squared curve.

Because of that, I'm really not wild about the idea of playing through on HARDER difficulty levels when I was already starting to struggle. But at the same time, starting a new character is kind of meh. Sword swinging seemed like it was a lot harder, and I cannot even imagine trying to play as an archer when the game loves to pour oceans of goons on you at a moment's notice.

Any advice or words of encouragement from the veterans of the community?

The last few areas of act3 are a lot harder than the rest of the game. Act1 cruel is easier.
Also, screwing up your first character is a given unless you follow a guide. My first character didn't even make it to cruel. You will learn more and more and your characters will get stronger.

it gets harder, but challenges are the game

not sure what advice you're looking for, but minion master is very popular --- not sure how great they are in mid-levels, but it sounds like they're pretty strong late