Hello, i have a problem, that is i cant connect to gog and because of that i cant update my games at all. I can access the store and my profile but i cant connect to gog when on game launcher, and using the blue "CONNECT TO GOG" button redirects me to redeem gift code page for some reason....

My guess is that you have installed the game from a retail version but you did not redeemed it on Gog.

are you using galaxy?

I bought the GOTY version, there was no code in box
Edit: TW3 GOTY, for clarification

Mine had a a printed piece of paper with Gwent and on the back it had the Gog.com game code.

Seems like buying used game from private seller wasnt a good idea. Is there any way to maybe update without GoG?

The booklet was not included?

The Witcher games are on sale quite often here. One way would be to wait for a steep discount and buy another (digital) copy here.

Another way would be to take photos of the box and the contents to prove you own the game, contact support and say "pretty please". Maybe they are nice enough to give you a key...

The original key should be revoked (or transferred to your account) by the way, if the previous owner used it, because he sold the game to you.
PS: Just found this: http://www.witcher3live.com/2015/07/download-all-witcher-3-patches-latest.html

I don't know if this is legit or reliable, although I very much think that DRM-free gaming should also include to get all the patches for an owned game without having to login somewhere, like pages like patches-scrolls provided for ages.