First of all, take a deep breath. You need to not only capture her, but get her to the vet. It is possible that something is wrong medically, and she is in pain, which is why she is lashing out. I know you are afraid of her right now, but even of you have to dress in a winter coat and mittens, boots and jeans over jeans - two layers, you need to go in there. If you can talk to her, you may be able to calm her down some, but what you really need to do is get her to the veterinarian first thing in the morning. You may need to "burrito wrap" her to get her in the carrier, but this is an emergency. In fact, if you can get her now, and put her in the carrier tonight, you can give her some food and water in there, and take her to the vet in the morning. This is NOT normal behavior for a cat, any cat. Something is wrong.

The vet's office would not immediately suggest putting her to sleep for good, but they will likely have to sedate her to examine her. She has lived with the hernia for 6 years, but bring any medical records you have, just so they will know everything they need to know.

Once she has been checked at the vet, there are certainly cat behaviorists out there, but I have a strong inclination that there's some medical reason for her acting out.