What to do for stronger, healthier nails?

I've worn acrylics or done fakes myself for so long, I'm messing my nails up. My husband always complains because even before marriage or knowing him, I've always had a super bad habit of biting my nails. I'll pick and bite them to the point that they'll bleed or running water over then washing dishes or whatever HURTS😭😭

What can I do to make them stronger and healthier looking? I know the nail beds will never grow back like they are supposed to.

Also. I get these dents under the cuticles on my thumbs.

What can I eat or should avoid eating?

What should I use?

Trying to stop biting them. When they do grow, they peel off 😑 I'm currently taking Biotin. But it isn't helping. My thumb nails grow no problem. It's the rest I have trouble with leaving them alone. **Sorry for my ugly nail pic haha**

Help meeeeee! Lol.