Would be interesting to know how long this usage went on for. Regardless you are spacing it out enough to give the brain adequate time to readjust to not having the medication, so you should avoid any withdrawal. I could see someone with steady use like this for like 3+ years feeling a bit off and some rebound anxiety. The longer you have maintained that use the stronger the mental aspect, knowing you don't have that mental crutch.
BTW is you do start feeling w/d it will happen within 3 days. The way you are taking it I would look at it like this.... if you go 24 past your expected dose without taking it and have no issues, you should be in the clear.
If you do have issues with it or are overly concerned to abruptly stop, you can always taper the use. You didn't dose very often but 1.5 mg is decent sized dose, I can't see any reason not to taper it.