songs skipping/deleted on iPod

Hello, i'm writing here because i don't know what else i could do to fix my problem. About 2 days ago, my ipod sort of deleted 20% of all my songs. I used to have about 4GB available, now i have 14GB. When I'm playing random songs, it just skips a couple of songs until i can get one that works. I looked on itunes to make sure that my files were right and my songs never moved of folder. On the main itunes page, everything is fine. Though, when i click on my ipod and i check what is on it, a lot of songs have either a weird circle or an exclamation point next to them. It feels like every time i sync my ipod it just gets worse.

I have tried reseting my ipod a couple of times, i have synced my ipod, i have transfered what i had bought.

I know that i might have to restore my ipod but since i have about 3000 songs i would like to do this only if necessary.

What else could i try?

What the songs look like on my ipod from itunes:

Here is how most of the songs look like on my ipod: