Sometimes I wish I had the instruction manual to life, this way I'd know what I was doing wrong. If such a thing existed, I imagine there'd be a chapter on 'Coming from the wrong perspective and how to stop it'. Maybe another would be 'How to manifest when someone's blocking your every move'. With that second one, it may include 'When multiple people are blocking progress'.
You know those times where you're working so hard on making progress and things are going so incredibly well (you feel yourself in the flow), then all of a sudden you come across people who don't want to budge, based on them not being able to see the way forward as clearly. You can see the most constructive and healthy way forward, as clear as day. It can even be in a way that serves everyone. But, nup, they're just not budging. Nothing you say or do will lead them to move on. I admit to being guilty of this myself at times, not budging, which drives some of those around me to frustration.
The relationship with your partner has taken everyone into a new stage of life but it sounds like you're the only one who can clearly see this new stage. You're partner maybe can't fully recognise it, his sister can't recognise it. Who knows, maybe one or both of his kids can. I think younger people can generally feel when it's time to move out and move on with life. They begin to feel certain limitations which don't allow them to move to the next stage. Maybe the question comes down to how to lead people to recognise a new stage of life. If they flat out just refuse to look at it, that's a whole other story: What to do when people choose to ignore things. Do we detach from those who ignore or do we work around them, working with all the aspects that suit us? As you can see, I have more questions than answers.
I can relate to resentment and not being able to entirely shake it and it agitates me. It's definitely an agitating feeling. I hate vibing in resentment. Hate the feeling of being on a low when I absolutely love the highs in life. My 16yo son and 19yo daughter lead me to highs whereas my husband leads me to feel lows. He's a non budger, a 'that's just me, that's just the way I am' kind of guy who feels no need for the relationship to evolve beyond what it is - deeply unfulfilling.
I've found when the vibe is high I can see the next move clearly. When it's low, only the blocks appear. Maybe the challenge is to manifest a higher vibration for ourselves and things will appear clearer.