Being on Day 7, you should have a fairly good idea of how bad the initial physical WDs are going to be....by Day 7, I felt like I was in hell and I jumped from 5mg. Of course, I used methadone for about 1.5 years, so you have a short time frame on your side.
It was very wise to stop taking it after 4 months, you really do not want this stuff getting deep in your bones, it is a beast to overcome, but it can be done. I am a 40 plus day survivor and making progress daily.
Gnarly said a mouthful about the post WD challenge.. it is definitely a grind and will not provide an immediate breakthrough moment that I started out looking for, but when you look back you can see your progress, so stick with it.
Not sure about the urine screen, there are so many variables, including your weight/fat%, metabolism rate, depth of panel screening, etc.
This site will give you all the information, motivation, and insight you need to overcome...keep coming.
Typically, I believe it's in the urine around 3 days, but it really has a lot to do with how fast you metabolize it, so don't take 3 days and run with it! Also, the panel test will have a lot to do with it.
Acute withdrawals last about 7 days for Methadone. Post Acute can last quite a bit longer... for 30 days or so. This is a generalization, it has a lot to do with the person, it is an individual thing, but this will give you an idea.
HI and welcome to the forum....well you have found yourself in the methadone trap like many of us...I was on it for 6 1/2 yrs ..first know this....your habit was short on it your dose not that high...but the withdrawal can be tuff...we have been getting a lot more short term users here lately ...the withdrawal is different for everyone but for most the physical part last about 2 weeks if its had enough time to get its claws into you...your borderline ...its not so much the initial withdrawal thats tuff but the post withdrawal sickness that makes getting off this stuff
so hard...its really hard to say how long it will last ...again you have a lot on your side
but I would expect at least a months recovery time to your back to feeling like you have energy again and are getting a good nights sleep witch will help a lot with the energy thing
for me it took a good 90 days to start to come out of it but my habit was 10+ yrs on the pills and 6 1/2 on the methadone so my withdrawal was bound to be long and hard
jumping off at 15ml is kinda on the high side so your really going to feel it at first with a little luck you will beat the long hard post withdrawal period ...keep posting for support
we all want to see you make it....this forum was a life saver for me...good luck and God bless.....Gnarly