My parents are divorcing. What do I do?

I (17M) don’t know what to do with my parents divorcing. My dad moved away this fall for work down to Cali and I live with my mom up in the PNW with my sisters kids. My mom and dad haven’t had the best relationship the last year and they tend to disagree on a lot of things. My mom and I went down to visit him this week. My sisters kids are staying with a family member for the week. The trip was going great until an argument started between them. They have been considering divorce for about 4-5 years now and they finally agreed on getting a divorce mid argument and my dad left the hotel to go back home to his house. We are currently still on vacation and have 2 days left till we go back home but don’t know what to do anymore. My mom is extremely sad and depressed and feels helpless and it breaks me to see her like this. I’m an American football player and enjoy going to the gym and that’s all I can think about 24/7 at the moment to keep myself from thinking about it. I don’t know how to handle this and how to support my mom through this. I am quite upset at myself that this may be my fault due to some habits (excessive eating, excessive spending, laziness, poor school performance etc). I can’t stop thinking that I had something to do with this and how I could have prevented this. How do I manage to cope with this? Anything helps. Thanks.