If you mean days, I am at 60 days clean off cannabis. But I'm about 3 months off of finishing a long taper off of adderall and an antidepressant so I am having some weird things going on.
Melatonin is not supposed to be used for a long time, though, and I'm not sure why. Over 5mg is supposedly ineffective from what I have read.
There are combos for sleep that one can get at a health food store. I remember Melatonin works really well with GABA, which also is a calming agent used alone for anxiety. It's an amino acid and very mild, not likely to cause any adverse effects on the healing brain. Not sure about melatonin so much, though. Some people have bad things to say about it online.
I have to agree with your mom - those PM things are a whole other class of drug really and may be hard on the liver over time and who knows how you're really responding to them on some level as your brain tries to heal. Those kinds of drugs used to always make me feel really weird the next day - like I'd been strung out on something. I'd stick with natural things as much as possible.
The safest things are probably the simplest things like warm milk and the tablespoon or raw, unfiltered honey. A turkey burger might do it too.