Sorry about what you are going through Robyn , and I can relate.
Try to reduce any point loading by using a wash cloth to line your skin so that hard edges of the Aircast do not impinge on sensitive areas of your foot and ankle directly.
If you can find thin soft foam, you can cut this to line the Aircast in those regions.
I get good temporary pain relief from soft ice packs , and if the leg is propped up ideally so that you can't move too much, you may not have to rely on the aircast quite as much.
You may get assistance sleeping from OTC Benadryl (diphenhydramine).
You can also get melatonin and herbal valerian root; these are generally regarded as safe.
I try not to fear the pain , but instead acknowledge it and just try to get through 15 minutes at a time.
I download free audiobooks from my public library website and listen to these while wide awake at night. I like to have some boring stuff downloaded too!
I also like listening to podcasts and inspirational stories of people overcoming major obstacles.
I like to use a white noise generator app like "sleep pillow" which can be mixed in along with either a podcast or an audio book.
Try not to look at your electronic devices very much in bed at night because it can disrupt circadian rhythm (day/night sleep balance) making it more difficult to fall back asleep Again. You can get blue blocking tinted glasses on amazon for less than $10 that filter the tablets' light towards a warmer color which reduces sleep disturbance.
I also listen to relaxation self-hypnosis "meditations" on YouTube .
Visualize yourself in the future
Doing your favored activities. You can make it happen.
I recently ruptured hamstring tendons , avulsing them right off the pelvis.
I too have tendonosis. Expect this to slowly improve.
Eat well and have more
Protein than normal.
I hope this may help you.
Be glad you are a woman....... you ladies are usually a lot tougher than guys are.
Don't forget to Listen to comedy.
It is a wonderful tool to assist coping.
Sending healing wishes your way- Walt