I take cuttings off my spotted philodendron, once I was trimming and just stuck the trimmings back in the dirt with the original
plant. I didn't think they would live, but I had plenty so I just got lazy about it. These did better than any others. If you are getting new growth its a good sign, your
plant may just need some time to recover. If you think the
plant might die try saving the healthy young part. You might try taking the top few inches off and and rooting them in a sterile meduium with a little rooting hormone.