Seeking Peace in My Du'a: A Heartfelt Struggle

Assalamu alaikum. For around 6 to 8 months now, I’ve been making du'a to be reunited with someone so we can build a beautiful, halal relationship. But honestly, I can’t shake off this stress and doubt inside. I lived as an atheist for many years and did a lot of wrong things. Even today, I’m still fighting some bad habits I haven’t fully left behind. There was a time when I hit absolute rock bottom-mentally and emotionally-and felt like I’d lost everything and everyone. That’s when I turned back to Allah for refuge. I wrote out a long, sincere du'a for this person I hope to reconcile with. There was nothing selfish or harmful in it; I only wished goodness for both of us. I’ve repeated it so many times and truly repented. Even though it’s long, whenever I make this du'a, I feel a deep sense of relief and peace wash over me. I start feeling hopeful, like it might be accepted and everything will turn out well. But then my mind goes, “What if it isn’t accepted?” I really struggle to just trust that “Allah will bring what is best for me” and move forward with that peace. My family and I went to see a knowledgeable shaykh. He told me, “There doesn’t seem to be an issue with your future marriage; the real challenge is just in coming together. Their feelings toward you are pure, sincere, and serious.” That gave me so much hope. But still, I keep worrying, “What if one of us makes a mistake and it all falls apart?” I don’t want this to seem like some passing infatuation, because it means everything to me, and it’s causing me a lot of pain. Part of me wants to believe in my du'a and the shaykh’s words, so I feel hopeful. Another part is scared that Allah might have someone else written for me, or that my du'a won’t be accepted, or that the outcome won’t be as beautiful as I hope. I don’t believe this person is bad-if they were, I think the shaykh would have said so. But I feel our understanding of relationships might be a little different, and that really saddens me. I mentioned this in my du'a, too. I also promised that if my du'a is accepted, I would perform a prayer of gratitude and feed some stray cats. I’m still young, and I wasn’t sure if my family would support a bigger promise, so I kept it small and something I could manage financially. Does saying things like that help a du'a be accepted? Sometimes it feels like Allah isn’t hearing me. Then I get even more scared, because I worry that thinking that might harm me. I know good things take patience and time, but mentally and emotionally, I’m just drained. How can I know if my du'a has been accepted or will be? What should I do for it to be accepted? What kinds of du'as are more likely to be answered? Sorry if I rambled a bit-I’m using a translator to write this, too. I really need some guidance because I feel truly desperate.