No right or wrong decisions

So I’m reading (again) the intro to the decisions workbook. On the second paragraph on page 9 it talks about changing your mind is always an option but often people don’t want to let others down so they don’t want to go back on commitments they have made.

I found this really interesting because I am a very loyal person and if I say I’ll do something, I’ll do it. And I expect others to follow through as well (otherwise I judge quite harshly). I started thinking about this in terms of my relationships because I take relationship breakups very hard (or disloyalty in any friendship) and there’s often variations on theme of “But you said [I was the love of your life/we’d do this/etc]” so then I think I feel duped because why would they say that if they didn’t mean it or had doubts. It feels unfair. I think I see a theme here that I am playing into the victim role when someone makes a decision that affects me / changes their mind?

Then I’m thinking about my current relationship which broke down last year but we’re talking about getting back together, but by getting back together – and keeping in mind this teaching – I am also giving him permission to change his mind and leave me again and I’m just supposed to be cool with it? Scary.

I’m not sure what my question is exactly here, sorry.  I’m more working through these thoughts and can’t quite put my finger on what the dissonance is for me, but happy for some direction! But what I can see are issues for me:
1. I have high expectations of other people to follow through on what they say (my manual for them) but shouldn’t we have some expectation of this otherwise we’re all going to be very flippant?
2. I fall into victim mode when they “change their mind”
3. I feel this opens Pandora’s box of uncertainty in every situation / relationship and that feels exhausting to me because it’s like I need to then plan for every contingent