Take a look at some guides for your character types. You might be doing a bit more role playing and not enough combat specing. I mean not everyone in Faerun can hold their own with a goblin or giant spider. So make sure you’re not making all the wrong choices by mistake.
Also, I got wrecked in a few battles of Act 1 as well. Anytime I fight Githyanki I’m thinking, “Well, there goes half my health potions and revive scrolls.” Don’t be afraid of save scumming and don’t be afraid to stack the deck in your favor. Long rest, drink elixirs, apply buffs, strategically place exploding barrels, and summon familiars if you expect a hard battle. And unless you’re fighting a “boss” or an enemy that has lines of dialogue don’t get concerned about pushing things off cliffs. With most you’re not permanently losing good gear.