Facelift last October, doctor did an additional procedure in his office. Now have hanging, lumpy neck. Options? (photos)

Surgical options for a neck have to address the fat below your skin. The muscle laxity. The deep structures under that muscle which include the submandibular glands, the digastric muscle and the fat between them (interdigastric fat).
Without an exam it is an assumption. However it appears like much of the fat was taken away without addressing any of the other deep structures. When you do so you can create this deformity.
I believe that a board certified plastic surgeon can help guide you repairing this process. The procedure I described above can be done through a small incision below your chin. I hope you find someone who can listen to your concerns and create a surgical blueprint to achieve your aesthetic goals.

This is a "cobra neck" deformity secondary to excessive removal of fat/tissue in the middle of the neck and/or separation of the muscles that were repaired in the midline. I would highly advise against a Kenalog injection as this is not simply a poor scarring problem. I would highly recommend a revisionary neck procedure to directly visualize and fix the problems. These are all my own opinions based on the photos provided. I would recommend seeing an actual plastic surgeon who has great training (in a 6 year plastic surgery residency or 3 year plastic surgery fellowship) and experience in facial aesthetic surgery (usually completion of a 1 year aesthetic fellowship after the other years of actual plastic surgery training.)

I wonder if your surgeon performed a platysmaplasty. If so there would be an incision under the chin. It appears you have platysma bands which need to be addressed. It can be done as a simple procedure under local in many cases.

Much more information is needed, such as a copy of the operative report to find out what kind of facelift you had, and a full set of facial photographs from all angles to Look at your neck, face, and placement of the previous incisions. From the limited photographs, there appears to be residual fat deposits in the neck, loose neck skin and asymmetry of the platysma Muscle bands. A revision lower face and neck lift should give you significant improvement. It Is very important to choose your surgeon based on extensive experience producing natural face/necklift results. Study your prospective surgeon's before and after facelift photo Gallery, and make sure that it is extensive with results that you like

That doesn't look right and unless it is all scar tissue, Kenalog is not the treatment. You should seek other in person consults from qualified plastic surgeons and will likely need a total redo to smooth the neck if there is extra skin and fat pockets.