Privacy and integrity in your own thoughts and explorations is a valid concern and basic need. You have every right to say "this is mine and does not concern you".
Establish limits and set boundaries, if you have to. If that means a locked room, desk, trunk, or other means, then do that. Often the best way to establish boundaries is to assert them.
You situation sounds intrinsically toxic. I understand you're married with family --- if that's where the privacy issues are (rather than at work), you might want to consider family counseling. A lack of basic trust or respect is a bad sign.
Meantime, digital encrypted systems may be more appropriate, though personal notations and code can help with paper --- you're not the first person to have nosy neighbours.
Establish limits and set boundaries, if you have to. If that means a locked room, desk, trunk, or other means, then do that. Often the best way to establish boundaries is to assert them.
You situation sounds intrinsically toxic. I understand you're married with family --- if that's where the privacy issues are (rather than at work), you might want to consider family counseling. A lack of basic trust or respect is a bad sign.
Meantime, digital encrypted systems may be more appropriate, though personal notations and code can help with paper --- you're not the first person to have nosy neighbours.