A small problem with a multi sig wallet

[o_e_l_e_o]

For sure 2-3 multi sig in bitcoin is not worth it.

I wouldn't say that. A multi-sig set up, while more complicated to use and recover than a single-sig set up, provides some unique benefits and can also provide a lot of additional security. The problem is that a lot of users, like yourself, are unaware of the need to have all the xpubs for recovery, and therefore the requirement for every signatory in the multi-sig set up to back up every other xpub along with their own seed phrase. For a 2-of-3 set up, the simplest way of backing things up would be as follows:

Back up 1: seed A, xpub B, xpub C
Back up 2: xpub A, seed B, xpub C
Back up 3: xpub A, xpub B, seed C

[BlackHatCoiner]

No, I realised that would be impossible, tried different ways, even if I learned that it may be possible to get a infinite list (still impossible) of addresses just with 2 of them and by luck to be able to sign a reedem script.

Do you have the 3 individual public keys that are used to generate the multi-sig address?
Do you have 2 out of the 3 seed phrases? (or private keys)

If it's a yes to both, you can recover your money. If you don't have 1 out of the 3 individual public keys, then you can create infinite addresses. The task of finding your multi-sig address' lost public key is equal to searching for an address by picking random public keys. You're never gonna make it.

Note that I'm using the term individual to distinguish it from the master public key.