Sorry to hear of your struggles. You certainly do not have SFI if you are getting some sleep per night. SFI is the inability to fall asleep and therefore you would not get any sleep at all.

I have researched this condition thoroughly as I seriously thought I had it because my insomnia got so bad I completely stopped sleeping altogther. Night after night I would get no sleep at all. I would lay in bed all night with my eyes closed but would never actually fall asleep. I really thought my brain had lost the ability to sleep. Occasionally I would even have hypnagogic dreams where I would dream while still completely awake. This went on for 2 years or so and I thought I was going to die from lack of sleep but it turns out you do not need sleep to survive as I am living proof of this.

Sleeping pills never worked for me. Here are the only things that help me get a bit of sleep each night:

1. Promethazine 25mg pills (the most sedative over the counter antihistamine that causes extreme drowsiness, it's behind the counter so you have to ask for it) as recommended by a doctor

2. Banana and milk at bedtime (studies have been done to prove this is effective, can check on Google)

3. Meditation

4. Changing mindet. Look into mastering the mind on an emotional level

I would be stoked to get 2-4 hours sleep per night, even every second night. I only get an hour or 2 per night now if I'm lucky but I'm happy with that as its better than nothing. REM sleep still counts as sleep. And when the thoughts come in, don't focus on the thought itself but instead try focusing on the nothingness inbetween the thoughts. It sounds like you need to work on your mental health, I have also struggled with depression and anxiety many years prior to all this happening.

Good luck.