Thing is, tho, anxiety IS a mental health condition. It doesn't matter that you were able to get rid of it in 3 days after suffering with it for so many years.
Clearly its very existence depended upon psychological issues that you had as a result of your romantic relationship. Mental conditions CAN be resolved by changing your life. If you'd had psychotherapy where you addressed what was making you anxious, you likely would have figured out sooner what the problem was. And arrived at a solution much sooner.
I'm not dissing you for that. Just making a point. Lots of people end up doing that to themselves. Hell, I was once told by a doc that there was nothing wrong with me that could be fixed by medical treatment. I had to change my life. It took me three years (and one suicide attempt the night I got that advice) to actually make that change--to leave my husband. All that time I had not sought mental health treatment. My husband insisted on picking my therapist, saying it was his right because he had to pay the bills.
You see the problem?
I told him I didn't need it after all. Somehow I got thru three more years of hell.
Since then, paying my own bills, I have been in and out of therapy many times. And each time it has helped me cope with new situations.
Please reconsider your assessment that you weren't REALLY "mentally ill" after all. That feeds into the stigma associated with seeking mental health treatment.
We live in a very sick society that creates conditions ripe for mental health treatment. It is the nature of modern society to do that.
Some people are more able to cope with those social conditions. Others haven't yet acquired the ability to recognize what's going on and to fix it. The right therapist can go a long way toward helping you make the decisions to change what you need to change in order to restore your mental health.