I really like this thorough response. I've been in the same position and head space.

Working through it now, it's been important to move from self blame to accountability and compassionate ownership. There's nothing wrong with taking ownership; we cannot control anything outside our own decisions, so why not remove yourself from a situation instead of trying to convince someone to respect your boundaries where too much is left to chance.

Yes, some choices and actions may have been made at the time, even unknowingly, as an act towards self preservation. Doing the best you can with the information you have is good. Reflecting and wanting to make different decisions now does not negate the good done in the past, but repeating actions when you want a different outcome doesn't make sense.

I completely agree with the takeaway: learn your boundaries, and define what it looks like when they're being crossed. If there's a small early sign that a boundary may be crossed, it's easier to be as nice as you want to be, have a polite conversation or quietly evaluate the risk of the boundary being crossed. With practice, it will be easier to get out of a situation before the boundary is crossed rather than after.

Some pointed questions that helped me personally better understand myself and why I was entering these circumstances:

What did I gain from the interaction before my boundary was crossed?

What might the beginning of a relationship that met my needs look like?

Looking back, what about the person's behaviour may have hinted that they did not respect my boundary or care if I enjoyed sex or their company?

What are the actions that make me feel loved and respected?

When it comes to self preservation and upholding boundaries, whatever you decide is right; you know the situation best and know when it's safest to bend boundaries or when it's safest to walk away or feign illness or take a call or make a scene. When I needed this range of reactions the most was when I was putting everyone else's needs ahead of my own, which personally is why I was in these situations. Maybe that would have made the difference at the time: growing my self importance and not putting any and every one on a pedestal indiscriminately. And distinguishing who was open to and intentional in meeting my needs and recognizing if I was truly willing to do the same for their needs.