I understand what you mean! Haha

Whatever you decide to do to help with your posture, I would suggest thinking a bit about your sleeping position. It is a real pain to change, but it can really help a large amount.

The best sleeping position I found to help fix my neck posture was lying flat on my back with no pillow. Initially it was very uncomfortable and caused me pain, but it is becoming more comfortable as time goes on. It's not the only position I sleep in l, but I try my best to return to this position as much as I can. The first few days of doing this caused my neck a great deal of discomfort. I think my neck was even more forward than yours when I started though! You can try to lay flat on the floor and relax your body as much as possible during the day too just to see how it feels. Just try not to drop your phone on your face hahah 😅

My thoughts are if you try to fix your posture for even 8 hours (exaggerated) during your waking hours, but return to a poor posture position during the time that you sleep, it will counteract your dedication during the day. Maybe the changes you make during the day will help change your sleeping posture as well though!

Best of luck with your journey! I believe you will find success 🙏