At 14 it's important to be attentive, just like you are and I admire that.

There's a couple things that might be going on. With the regurgitation of her food, I'm suspecting an allergy (it might also explain the fur loss and lump).

Food allergies can occur at any time, even after years on the same brand. For the most part, we are all feeding our cats the wrong stuff as promoted by deep pocketed manufacturers with convincing ads and commercials. The ingredients can be (and often are) changed according to where manufacturers can cut corners/costs.

Sad isn't it?

The best way to start with ideal nutrition is to read ingredients on the cans (yes, canned foods are better overall). Name brands are not important, but ingredients are. Meat or fish should be in the first couple ingredients and not plant products. For example, "chicken, chicken liver..." or "beef, chicken ...", you get the idea. Not "chicken by-product meal" "corn meal" , "wheat gluten" or anything along those lines. Greens or vegetables of any kind are a waste of space. Not all proteins are the same either. Looking for the protein percentage on the label is deceiving if most or all of it is from plant material or by-products.

Even if you choose a kibble to supplement the canned foods it needs to have a real meat in the first two ingredients. You might be surprised at what could be on ingredient lists of some popular, very expensive cat foods. Many of these foods are no better (sometimes worse) than discount store pet foods and what the public would be shocked to discover is that sometimes they both come from the same manufacturing plant, using the same formula and just varying their shape, color or size and packaging.

This was something that became apparent during the recent pet food recalls.

For more comprehensive information on feline nutrition, by a vet who specializes in this research and offers findings and suggestions freely, check this site: http://www.catinfo.org/

The other consideration for her condition is a thyroid disease and/or diabetes, both very common in a geriatric cat like this.

The link above will also discuss how to address these diseases with nutritional changes.

It sounds like you are very devoted to her and I wish everyone was like this.

When you take her in to diagnose what's going on, make sure your vet does a T3/T4 blood chemistry along with the usual eval in order to better detect any thyroid disease.

Of course you might just try the nutritional modification to see if things change in a week or so. If not, the vet visit is really necessary.

Good luck and let me know how it goes.