Thoughts about insomnia

Hi, I am working on insomnia. I have no problem falling asleep but I wake up after 4-5h and struggle to fall back asleep. Its been an important experience through my last 7 years, with worry and frustration visiting me at night, and resentment and victim mentality in the mornings. I did some work around it, I can get better to deal with negative emotions, however, I have the expectation to be able to improve my sleep in the long run. As this is not happening, I feel stuck.
Beliefs around my sleep at this moment are:
– Having insomnia means I am a victim of my brain and body -> F: victim
– My body will carry the burden of all these years of somatized stress -> F: worried
– Insomnia is an obstacle to my concentration, performance and ultimately to the achievement of my goals -> F: dejected

So all of this is actually just a premise. Today I thought to focus on something more specific, ie. the fact that this insomnia arose when I started working out in the gym, years ago. I tried to look back to my thoughts of 7 years ago comparing them to my current ones and noticing what changed in relation to this C: empty stomach/ lower sugar at night
before gym: this means I can have more food next morning -> F: excited -> relax -> back to sleep
after gym: I ate too little, I am losing weight, I am losing muscle -> F: worried -> tensed -> keep rolling in my sheets
With respect to the last line of thoughts, I remind myself these are just thoughts, and that it is just my primitive brain fearing death, but apparently, I am still holding onto them and I very rarely get to a complete emotional shift. Any suggestion? Thanks.