t matter what I do, what configuration I make, everytime the hair gets messed up in unity.
Any tips? I'm using unity build in shaders.

That's not from the shader, that's from the physics.

Unity's PhysX for Cloth physics is very temperamental when used on Hair due to the very dense meshes. You can try to make sure that the Cloth component is not using any self collision in the cloth constraint editor (the second of the two buttons at the top of the cloth component) and you can make sure the stretching and bending stiffness are set to 1. But the mesh may be too dense for Unity Cloth to handle.