I cannot make my game stable with cc.

It's also important to make sure you have all the files for any particular piece of custom content. Such as many more complicated cc requires master parts, and slaved to different parts. Some things don't work correctly and are slaved to a master, without the master files or object in game you may crash or some things not show up at all. That's why it takes time to remember creator notes. And why it's important to not go deleting and removing cc all willy nilly. Even if you do see a duplicate. It's also important to know the creator's work, and make sure they never name their meshes the same thing causing GUID conflicts. It's also important if you are using a lot of decor and building material you have downloaded that you rememeber if a fence is really a fence or just recolored decor to look like fences, or if columns are really columns or just retextured decor from a painting or something. Or if OSMPs also are invisible and may cause the builder problems if they don't remember they are invisible with some of those. Considering you said you don't play but build then I would start with all my building materials and all my decor items and pay no mind to clothes and hair since you are not actually playing.

ETA: Rules to Remember, don't try to use lots that were built while a SP was installed that is no longer installed, game crashes.

Don't delete cc from game if that object or decor is still on a lot, delete/sell it from the lot first or the lot may never reload or crash.