My scale is an A$$hole and I want a divorce

Great title! Sometimes we plateau and we have to work through those. Those losing any amount of weight will say that the last 5 pounds is killer. You are doing a great job and have persevered amazingly! Could be too that some of that is lean mass which weighs more than fat mass. Additionally, keep doing everything you know to be right -- don't cut your calories a super-restrictive amount or you will go into starvation mode and not lose anything. You know what you have to do and I've no doubt, given your 20 month track record, you'll do it! And, by all means, divorce that thang!