He's one of the harder non-optional bosses, but it shouldn't be too bad. One thing about FS games is you should almost never feel like you're hitting a wall. It's antithetical to the design of the game. When you feel stuck you're supposed to go somewhere else, find more equipment, level up, upgrade your gear, etc.

People play other games where they are forced to slam their head against a boss until they win, then they hear that FS games are hard, and then they expect that FS expects you to do the same thing. Yeah, the games are hard if you play them wrong. They're pretty easy if you don't (not including some optional content). You're supposed to go explore and come back stronger. You're also supposed to pay attention to the weaknesses of the boss and adapt. For example, Maliketh can be stunned by using the Blasphemous Claw, which is found nearby.

One additional option is summoning help. This is in the game for a reason. Sure, some players say you didn't actually defeat the boss if you summoned, but that's dumb. Why would they include a feature in the game if they didn't want you to use it? They've been including this since Demon's Souls, and they don't think it ruins the game. Why should you?