Where Do I Start With A New Thought?

Good morning! I’ve been following Brooke for 2 months, and can do models on most areas of my life. However there is one GIANT area of my life where I feel stuck. My son has time with his dad every other weekend. As soon as I get home to my empty apartment, something happens to me. My brain feels like it short-circuits and then I feel overwhelmingly exhausted. All I can do is lay on the sofa and half sleep/half listen to romance novels in Audible until it’s time to pick him up. I have lots of thoughts that are all based on experiences that have happened over and over the last four years (since we divorced): my son’s dad might not give him back when it’s time, my son’s dad might say or so hurtful things to our son, this is going to go on for 13 more years, I don’t know what to do with myself when my son is not with me, etc. I just need a place to start with a new thought. Something that will allow me to begin having a tiny bit more energy so I can begin to enjoy my own personal life again.