Large Unneeded hitboxes

hey guys. So im currently developing a game, and the main character has a giant hitbox even though there is empty space in front of him. could you leave a step by step solution to the problem? thanks. also, could you figure out why my character keeps glitching/lagging when moving. thanks so much

Right now the hotbox is a circle, changing it to a rectangle will fix the problem

Ornyou could try a proximity instead of a collision