I've removed the whole scene and all sources that was referencing the camera that had filters... everything is fine again, i've just had to recreate my scene and the sources that were in, and OBS seems to Rock again... Now that i see more clearly, the problem comes from the chroma key filter.
On both windows profiles (2 distinct obs projects), i was playing with green-screened photos or green-screen with the cameras. The problems came from the moment i introduce the chroma-key filter.
For the moment, i use gimp to remove the green-screen of the photos, and OBS is still up and running, no CPU problem, nor any crash....
So is there a problem with the chroma-key filter in general ? with Win10 ? with specific hardware (i use 3 blackmagic design decklink mini recorder) ? My windows 10 is up-to-date, i have Kaspersky Anti-virus (but, though it may be a problem sometimes, i don't think it can interfere this time), I run a I5-7400k, with 16 MB, a 500 GB SSD (with 200 GB free), a GTX 1050 with uptodate drivers. I'm Running a 22.0.2 OBS Studio / 64 bits.
If you have ideas or correction, i can test if you need to. Now i know what to do, and what to NOT do :)
Regards