Nail vertical lines?

I really wanted to try gel nails when they first came out.

I don't feel like doing it.

They sold a lot of gel nail sets on home shopping.

I bought it then, applied it diligently, and also removed it.

I tried applying it again..

At some point, my fingernail started to lift from the flesh...

Rough vertical lines are appearing on my nails.

So, I haven't done it for a while..

But the nail lifting has gotten better..

The vertical lines on my nails won't go away.

Could it be because my nails have become thick?