How to give my cat back her freedom

I’ve only had dogs my entire life so I’m very new to this whole cat world. However, a few months ago, I fell in love with a feral kitten and took her into my home.

Everything was going well until last week when she disappeared for a day. We literally found her in a small tiny hole in our kitchen we never even knew we had. We have no clue how she fit herself into it and how in the world she survived for 24 hours in such an airless location.

Since then, we have been terrified to let her roam our house. She stays in our bathroom. Prior to her disappearance, we left the bathroom door open and she came out as she pleased. However, we are now afraid to let her out of the bathroom. Partially because we haven’t patched up the hole as yet and partially because she continues to exhibit the strange behavior that she exhibited prior to her disappearance, specifically frantically darting from one end of the house to the other as if she was in a panic.

This has me feeling awful. It’s obvious she doesn’t understand why we won’t let her out. In addition to that, because of our busy schedule, we don’t have a lot of time to visit and play with her in the bathroom, meaning she can go hours without seeing us and I do not think she likes that much.

What can I do about this? How do I allow her the freedom to roam the house and be around us without her disappearing into another unknown hole? Furthermore, we still do not know why she continues to have these frantic episodes of panically darting from one end of the house to the other. It’s a very new behavior for her and given that she still doesn’t allow us to touch her, I have no clue how to get her to a vet to be checked out.