how do I determine I am in a secure relationship

How do I determine I am in a secure and healthy relationship with my beloved Nico? Last night I had a pretty big mental melt down (seems to be the pattern as of late - I’m going through another dark wave momentarily). Nico was also under-resourced, and he was able to find enough ground and resource to guide me through a meditation to help me calm down.

He was supposed to be home last night from his 5 day trip before I went on my 5 day trip, and he wasn’t able to make it home, so that means 10 whole days of not seeing each other. At the beginning of our conversation he had a twinge of defensiveness, and I was able to offer grace and space, even though I was not grounded. I had compassion for that part of him. I am so in awe of our ability to be kind to one another, even when we are both under-resourced.