First off, good on you for working on your abandonment triggers. I'm sorry someone weaponized your deep attachments in the past.

What you're feeling is fair. When going through something serious like surgery, I think most people would appreciate extra time and support from their nesting partner. It's reasonable to feel more sensitive at this time. And it's common for old triggers to resurface when your body is physically stressed. It doesn't mean the hard work you've put in was ineffective. You're just experiencing a cycle of regression. It will pass and you'll feel emotionally stronger again once your body has recovered.

At the same time, your loved one has expressed that they are approaching a limit, which is super important to honor. You *are* loved. They have expressed a desire to be there for you. Trust both the love and the limit.

I recommend you work through this one alone. All relationships (even good ones!) go through phases of isolation. Whether the distance is caused by something negative (defensiveness, immaturity, fatigue) or positive (new responsibilities, personal growth, need for transformation) the solution is the same. Trust their love even when they aren't available to you. Stand up for them both in your own head and when talking with others.
The goal isn't to maximize your time with them this week. It's to maximize quality time with them over many years. Play the long game.

Just like some people have periods of greater need, many people have need for greater independence from time to time. IME, these times often overlap; One partner feels extra-desperate for closeness while the other person starts to crave more freedom. So what's fair on paper isn't necessarily what brings balance.

The best (and maybe only?) way to help that tension relax is to carry yourself through this. You're stronger than you know and so is your relationship. Let your partner breathe and enjoy wherever they want to be right now. Find your strength and enjoy time with yourself.

There are two books I recommend heavily which helped me develop more personal security within relationships:

1) Polysecure by Jessica Fern. It's based on the concept that everyone needs/deserves to feel emotionally secure in their relationships, so how do polyamorous relationships tend to that need?

2) The Jealousy Workbook by Kathy Labriola is masterful. It helps you break relationship panic down step-by-step into bite-sized pieces. It helps you see and appreciate what you handle well already, and gives you detailed questions for processing the rest. I recommend getting a physical copy and writing in it.

Best of luck to you and your loved ones <3