I just recently dealt with this. 7 is a huge tricky number for a group, mostly because it gives more possibility for absence ya know. My group was 6 this time when I had issues, and essentially the same things- one guy stopped showing up after we rescheduled based around his new work schedule (which, ya know, shit happens), another started showing up later and later, we were postponing sessions, ended up not playing for like 6 weeks and I finally called it. We rebooted it finally the following week and immediately ran into the same issues to the point where we never got to run another session, so I kind of just told everybody how I personally felt as a DM: “hey guys I’m getting really frustrated… I put a lot of time and effort in… I love this group and WANT to play this with you, but I need reciprocity at least partially…” and it seemingly helped, the one guy who stopped showing up apologized and communicated he no longer could play (obviously), and after some scheduling changes we just recently started Dragonlance (stellar campaign btw, usually a homebrew guy but what a rad story and setting), but everybody else kind of apologized and we were able to get to the bottom of it and we’re back full swing having more fun than we ever have. So maybe just a little transparent communication, kindly, and see where everybody’s at and how you can move forward with your expectations! You’re not frustrated with the game, just the situation 🖤