Hello @mztrai, Welcome to Connect. I struggle with opening some bottles and jars but so far I am able to use one of the rubber pad grips to help get them open. I also use scissors for some boxes. I'm wondering if you could use a utility knife that has an razor blade installed for cereal and other boxes. They are fairly inexpensive and can be found in most hardware stores. I did see a unique tool for opening bottles of varying sizes that will get you more leverage and let you use more of your wrist and arms vs just the fingers. It seems to be a little spendy for what is is but if it works it may be an answer - Arthritis Bottle Opener - https://www.amazon.com/dp/B018KFII4G.

You mentioned difficulty buttoning pants. I found an inspiring video for how to do it without use of your fingers that might be helpful.

Have you looked into physical therapy to possible strengthen the hands and fingers to help?

Buttoning Pants Without Finger Function - How To | Quadriplegic (C5,C6,C7)