PLEASE give my recommendations for my old dog

Hi!! My dog is a lab mixed with a German short haired pointer. She’s 12 years old. Recently she’s been walking super slow, having issues sitting up. I want to try Cosequin. Does anyone who uses this think it works well? Also will it give her loose stool? She’s already having that right now as she wouldn’t eat her kibble but would eat her soft food from blue buffalo. My next question, she has severe allergies. We haven’t taken her in to the vet but I’m planning on taking her next week if I can’t do something now. She’s been licking her paw so raw it bleeds. The reason I’m not taking her in yet is because I’ve been home to watch her and I’m cleaning it but I’m going back to work and can’t. Does anyone recommend good sprays or wraps to prevent? I really don’t want to give her a cone and I’ve had her use the donut instead before and she just hates it. Please let me know. I heard fish oil may help, but I don’t want to keep giving her a lot of random new things especially with age.