Anxiety medication has helped me a lot with racing thoughts, hopefully it's the same for you. Other than that I would say try getting as physically and mentally comfortable as you can before reading. If you're stressed, anxious, fatigued, etc it will be hard to concentrate and read. Take a shower to relax muscles and nerves, get into comfy clothes, turn on some music works for me. Try to limit distractions as well. I read a lot easier if my phone is off and away from me. Last suggestion is to try to sleep better. Fatigue and eye strain make it very hard to focus eyes. An extra hour or two of sleep helps out a ton for my mood and ability to focus. I hope some of this helps, I know the struggle.