I'm going to have to go "blunt" route here. You need to immediately change your willingness to work after hours.
Don't give any excuses, just tell your boss that you expect to work the same hours as everyone else, including leaving when everyone else does. You need to state this in a way that prevents everyone else from having to stay as long as you currently are.
You don't need to tell them you are busy.
You don't need to tell them you have projects.
You don't have to tell them about your commute.
You don't have to tell them about how you need to rest after a long day.
You don't have to tell them about how you need to get away from the stress.
Be professional, not rude. If they remain professional and understand, great. If they become rude, push you to continue working late, or push you into coming in early, you might want to start looking for a new job. You may have already set expectations that you can't change at this position, so look for a new one, setting expectations in a way that actually works for you.
This is a job. They pay you for your time and effort, they don't pay for your private endeavors. If they want to get to know you, that's fine, but it's not part of the job. It's also not part of the job to ignore having a life outside of work.
Regardless what many other people say, the job isn't there to take full control of your life. That's nothing against other Answers, there's plenty of people you know that'll tell you to endlessly work, and that's a short path to burnout and truly hating your job, your life, and pretty much everything else.
You still need to do your job to the best of your ability, including improving your ability, but only during work hours. There may be times when you absolutely have to work extra hours, but those should be the exception, not the rule.
As a secondary though, your boss might be attracted to you. They may be working with you late as an excuse to be with you, or vice versa. Without knowing more about the situation, the romantic side is only a wild guess. You boss might be strictly business and just trying to get cheap/free labor from you, but maybe there's more to it. I'm just throwing this out as "possible".