Ugh, the Troll, OK you'll need a jellify spell, or an attack mushroom, or perhaps a goblin spike collar and a monster slayer. Or you can take him out in one hit with the basalisk fang if you get one, although I try to save the fang for the sorcerer.
The first thing you'll need to do is knock down defense with jellify, if you don't have jellify, but have a love spell and an attack mushroom, you could eat the mushroom, love the enemy down to 0 defense and then punch it to death, you'll need a base attack of at least 2 whether you get it through elixirs, grow mushrooms, enchanted weapons, the goblin collar, or a knuckle duster.
I guess you could eat 2 attack mushrooms if you had an attack of 1 but it seems like a waste to eat them both, I'd try to save one for later.
If you don't have the jellify spell a monster slayer should be enough to take out the troll, but you'll want a good shield, and maybe a smoke bomb, and heal potion wouldn't hurt.
A lot depends on what you get from the game by that point, remember to save your critical items like mushrooms and smoke bombs for these kind of battles, smoke bombs are great to avoid a gargoyle or werewolf, but don't waste it on a blob, just take the hit.