First, I am very glad to hear that he has ended his fast. I suspect it may have been due to discomfort in general with his forelegs but that lip licking did make nausea a concern as well. In any case, that is grand to hear and I am glad that isn't an ongoing worry now.
Further to this, when we see dragging of the legs, it can be a sign of weakness secondary to pain (common in older cats) or due to spinal/nerve issues. Now if he is resistant and sore when you handle the legs, I would be suspicious that he has feeling in them and therefore spinal/nerve issues would be less likely. And in that case I'd be concerned that we may be dealing with severe arthritic discomfort +/- a muscle strain/sprain causing this sudden decline.
Now with this being so severe and his being sore when lifted, I do have to say that it'd be ideal to have him seen by his local vet at this point. They can examine his legs, confirm our suspicions and start him on cat safe pain relief (since there are no safe OTC options for this species).
Otherwise, there are some long term supportive treatments that could be generally of benefit for him as well. Specifically, you can supplement him with fish oil (omega 3 or 6; EPA/DHA) and/or glucosamine/chondroitin. In regards ***** ***** former, these can be helpful as they do have anti-inflammatory properties. In regards ***** ***** we tend to give this at a rate of 20mg per pound of their body weight. And this could just help soothe any joint inflammation and be a long term management option with his arthritis. Furthermore, you can use glucosamine/chondroitin with Fez. These are a nutrient supplement that is available at your vets, pet shops, and health food stores (as as capsules, liquids, and even treats). They work to aid joint suppleness by helping cartilage replenish itself and blocking enzyme destruction of cartilage in the joint. Often we can find this helpful in animals with mild signs and this could just take some of the discomfort away from him. Normally we give kitties 50mg glucosamine + 15mg chondroitin a day per 10 pounds of body weight. So, these would be worth consideration here.
Finally, you may want to consider giving him access to a heat source (ie heat pad, warm compress, etc). Just like our sore joints, cat joints often respond to warmth. This will reduce inflammation and relax his muscles. Of course though, whichever heat source you use, do monitor the temperature closely, since we don’t want to overheat him and want to make sure he could get away from the heat source if he wished (which he likely would have no trouble but we'd always want to take care).
Overall, Fez's forelimb signs do raise some concerns here. Therefore, we need to tread with care. With how sore he is, I do think a check up and cat safe anti-inflammatories would be ideal at this point. As well, at his age and with his signs, I do think the above long term treatments would also be of benefit to him for the longer term.