I also suffer from E.D.. Of all the treatment plans Muse is probably the least desirable. When you have had a prostatectomy there are other treatment plans that can in a percentage of men restore erectile function. It takes a specialist to deal with this who is interested in trying to help you. The problem with prostatectomy patients is that often nerves controlling erection are severed in the surgery. However, often nerves which allow sensation may be found to be intact. The two better plans are injection therapy if it will work for you, and implants. There is an implant which uses a fluid. These implants are placed inside the "erectile chambers" of your penis and a small reservoir pump is implanted in your scrotum. As crazy as it sounds this works quite well and if your nerve structure for enjoyment is still intact it is a method that will work. Usually the cause for prostatectomy is adenocarcinoma of the prostate. I am surprised that your MD's did not discuss this option with you at the time of the surgery. These devices for implant have been around for some time now.
My personal objection to Muse is that you take a tiny pellet and implant it up the urethra just after urination with a device. You then break the pellet in the urethra which dispenses a dosage of an erectile drug into the nerve structures controlling erection. If the plumbing is still working you have an erection. My urologist did not like Muse first because it is expensive and secondly because it can cause urethral irritation.
My cause was an injury as a teenager that caused scar tissue as I aged. I was also genetically gifted in that my biological Father developed it by the time he was in his late 40's. He had no known health problems at that time.
The trick is that it takes an MD who specializes in treating ED to help you effectively. It is not cheap, but, you stand a good chance of getting help.
I can give you a couple of leads if you PM me.