I think you're doing really well. You've narrowed the focus which can be really helpful. It also helps me see some things other may miss because I'm a writer. So, I notice subtle clues and hook you've left in the story that others might not.
I would tell you to remember that there are different kinds of impacts a choice can have. Not all of them need to affect the endgame. Some can just impact how we see the character in our own minds going forward even if his actions and dialog don't change.
For example: If the next time Liza says she loves the MC, a choice to say it back could be impactful in the moment. She doesn't have any variables associated with her and the only thing it could change is the next render having her look happy or sad and then it never comes up again, has no effect on the end game. But in that moment, it was an impactful choice. We got to determine if the MC was just using her or really does care for her, even if he still knows he has to use her. We get an emotional impact, even if there is no story impact.
All that to say, I think you're doing a great job. Maybe you tried to do too much for this game starting out, it did kind of seem like you were trying to set up several possible ending with all the characters in different places in relation to the main character. But I think you are going the right direction for now and you can definitely get to a satisfying ending even if there are only one (maybe with only minor dialog differences) or two completely different possible outcomes. Just keep telling your story and I'll be here following along...
But if you don't give me a Megan redemption arc, I'm going to riot... just kidding... maybe...