Try getting an old-fashioned red hot-water bottle at the drugstore, and fill it at night and rest your foot on it and put a pillow on top of the blanket where your foot is. Since you're used to doing *something* with your foot at night, this might soothe the part of your brain that expects a foot thing at night in order to go to sleep.
If you are restricting blood flow for the entire night that's probably not going to be in the long term. That being said, if you've been doing this for the past 15 years and haven't noticed any side effects that is slightly encouraging. Consider this though, restricted blood flow means decreased oxygen to your cells below the constriction, which in turn leads to necrosis, which in turn may lead to permanent or lasting damage. If you can change your sleep habits I would encourage you to, perhaps some meditation or reading 30min before going to sleep. I would avoid liquids, stimulant's, and electronics at least 30min prior to sleep. If you're mind is restless have a pen and paper handy and take some short notes on what's on your mind and know it will be there if you need it.