I recently started creating a game and I'm having a lot of work to make a sprite for the game's main character, does anyone have any tips? some tricks or programs that you can use without having to draw frame by frame

A big benefit of moving to 3D is that they don't need to be individual frames, but it has a different cost of animation curves plus modeling.

For the 2D animation, there are tweening tools out there which can help with volume-preserving morphing, but an artist will still want to touch up the results for the sprite sheet. An alternative is to start with a 3D model and render it in the poses and viewpoint angles needed. It will always be an intensive art task, and modifications to the sprites get increasingly more work as the project grows and finishes.

Wow, i have not seen such drawing and shading skills in a while. :O
At this level i would not expect any help from software tools regarding animation.
But maybe you can ask in forums from the animation guys.
In games such high resolution sprites are rarely animated, so most of us don't know about tools, i guess.