I used to bite my nails and cuticles badly, but I've stopped now

My nails r now quite long but there's one problem...

They're flat and weird

Other people (for example my mom) have nails that r sturdy, and curved

My nails are flimsy, bendy, thin, flat, the line between the pink/flesh bit and the ends are wobbly and uneven?

I only quit a few weeks ago... what do I do?

Is is because i bit my nails for ages? (most of my life, I think)

If any of you have experienced this, how did you fix it?

Please help, bc I'm going back to school soon 😔😰😰😰