How do I cope with my lithro tendencies?

This is kind of a vent, but I'd also like some insight or advice, or someone who has been through something alike. (I hope I picked the right flair for this)

TLDR; I experienced a lot of stress during a dating stage and broke it off, because I'm probably on the aro spec. Being in the friendzone made me realise my love for him, and I'd love to try again. But when a relationship is no longer off the table I start to go crazy in a negative way. This love feels like it's unattainable and I could be showing lithromantic tendencies. How do I cope with this?

A year ago I met someone on a dating app, back then I did not identify as arospec yet, I also had never had any romantic experience. After being friendly with eachother for like 3 months we decided to date and we dated for like 6 months. I really liked him, but experienced a lot of stress, because I was not able to identify my feelings. I wasn't sure if my feelings were romantic, I felt like they were not enough to be called romantic the way alloromantics usually do. Doing some research on this subreddit and other websites made me realise I was probably experiencing alterous feelings. I also started labeling myself as arospec, because I realised romantic love might be difficult for me as a whole, despite really longing for it.

After dating for 6 months I decided to break it off by telling him "I'm afraid I won't be able to give you the same you give me" in regard to romantic love, and we decided to stay friends. We ended up still talking daily, but ofcourse our dynamic changed from how it was before, so no more flirting or hinting at dating. I was very sad about the break up (which was in march this year) and cried a lot, more than I expected. I, however, did not regret the break up, because it made me realise things about myself I was doubting/questioning during the time we were dating. Basically: the friendzone made me miss him a lot as my potential partner and made me think "Am I experiencing romantic feelings the way allos do?". I believed so for a while and was honestly happy about it. A few days ago he mentioned how he wishes I was with him, and it was the first time he mentioned something like that since the break up. It could be in a romantic way, or just a platonic way, not sure, but I was giddy about it regardless. I missed him, he missed me, great! This might end in something romantic! Yesterday he was having a bad day and he said he still had a few good things in his life, one of which was me. I was very giddy about it again, but after a while I started to feel... off.

It finally felt like a romantic connection, or us dating, was no longer off the table. I should be happy about it, but suddenly I started overthinking, about me, about him, about us... To be in a relationship with him is all I want, but why does it feel so suffocating only thinking about it? This is the first person I have felt a special connection like this with. It's like I want to be with him and miss him when we are not romantically involved, but get scared off and spiral from the moment a relationship is not off the table anymore. I feel less like myself when I imagine us together, like its wrong on my part. I get dreams about him being my boyfriend when we are not dating, but when I think too much about him being my partner I get dreams about kissing and flirting with other people I do not even like the same way. It's like a healthy relationship with him is something I will never be able to attain and it hurts me a lot. I have never identified as lithromantic before, but I feel like I am showing signs of it (or something alike?) and I don't know how to cope with it since it is new to me. How do I get over this person I do but also do not want a relationship with?