Hello there Arya

As I've understood it, Arya -as your fursona- represents you. But she never met your partner's OC, yet she has found courage and independence (as you have), which you feel is because of said partner's OC, correct?
That aside, you're not screwed. She is your character and you designed her (to represent you). In a way you have created a world with her in it. That means it is totally up to you what can happen. Various options could be:
1) You still design her backstory as you experienced it. The children you would have had, etc. that could all still have been what Arya wanted, but never got (right now) just like you.
2) Arya can still have the backstory, the children, etc. Run with the flow, as it were.
You can go in other directions as well, but how I read it is that you want your experiences to count for Arya, as she seems to really represent you, right?
I also want to add that -whether he dumped you or the other way around- as I read it, it wouldn't have worked out. You wanted more independence, and he treated you like you needed help constantly. It's never good to begin a relationship while one is in an extreme (depressed) state. A lot of people feel lonely and want to be with someone. And one they connect to someone they often -not always- start to fall in love and feel they found a (perfect) partner. A lot of the times it is to fill up the loneliness, or to get rid of the depressing feeling one way or another. If it wasn't him, it would have been you probably to put an end to the relationship.
Besides! You seem like a fun person, someone indeed who wants to do things by herself. Don't let someone hold you down like so. Find someone who values your company AND your independence

But don't look them up, just wait and see who comes by. See who 'clicks' with you. Just enjoy your life for now and what comes across your path, comes across it.
(If that makes sense?)
In other words: Learn from this experience and move on. You now know a bit more what might work and what doesn't work, so you know better what to look out for next time

As for Arya's backstory, take a moment to think about where you stand in your life. Meditating or just relaxing, thinking about Arya, might help. See what you can tell yourself about Arya's backstory. Don't panic ^^
And if you need some more help, feel free to ask (me or just here on TFF in general

).
Hope this helps in some way!