Couple things:
1) It sounds like you really just need a break. Can you take one? Can you ask a friend for help? 60 hrs+ on a whack sleep schedule is tough. Do you have blackout curtains, eye mask, or earplugs to protect your sleep?
2) How is your diet? Under stress if you are eating a crap diet (refined carbs, heavy sugars, caffeine, etc) that will impact your body far more and can even cause cyclical swings of anxiety that impact your ability to rest. See:
https://www.psychologytoday.com/us/blog/prescriptions-life/2...
3) Come up with an image of relaxation in the highest detail. It needs to be a scene where you feel safe, secure, and feeling the warmth of compassion from someone you trust. Maybe you're on the beach, in the forest, whatever, it needs to be as high detail as you can and engage all the senses. Colors, shapes, smells, textures, temperature, touch. Write it down, draw it out, own it, envision it using every single sense and emotion you can. Practice entering this scene for 20 minutes a day (set a timer) and feel every aspect of it. Take notice of the various details as you are in your scene. Don't expect anything from it, but just work on spending time meditating on and building it for 30 days. Practice this every day regardless of if you feel like it "works" for sleep. After about 3-6 months you'll have a tool you can use to relax pretty quickly, the feelings should follow about 15-30 minutes after spending time in your scene.
4) Insomnia blows ass, I've been there, but the long-term recovery is taking breaks as you need them, writing down a few key actions in your relaxation + nighttime ritual and sticking to it, exactly. Ex: Get tea at 11pm, enter scene at 11:20pm for 20 minutes, read book until I feel tired. Even if it feels like things "aren't working"... Also, get out of bed if you toss and turn. If you're not sleeping anyway, there's no point. Associating wherever you sleep with anxiety needs to end.
There will be ups and downs but you will recover. But absolutely please schedule in breaks to look forward to.