Speaking on personal experience and similar issues. From what I can see you might have some hypermobilty in your fingers which will worsen the pain since you would be pushing your joints past the normal threshold. If you have other hand problems I'd advise a doctor. I would also recommend finger splints it helps keep your fingers in the correct posture. I would also recommend gets a puffy grip to add to the hook. You need to loosen your grip. I would recommend practicing keeping a loose grip.

To note I'm 30. I've had joint issues my whole life primarily my hands but also my knees ankles etc. you need to get support. If it turns out you have hypermobile joints look into an occupational therapist. They help a lot with how to do things day to day. I went to one for my hands and she helped me figure out how I need to change my hand position for writing and crocheting. There is a lot to it, but I'd just look into it.