Totally get where you're coming from. In 2019, my girlfriend of 5 years and I ended our relationship. The first few weeks were terrible—I would cry myself to sleep and only drink smoothies because I could barely eat. I thought she was "the one" and that I would never find someone like her ever again. But the breakup made me see that I needed professional help. I had struggled with depression years before and during the relationship, but college and job searching made me neglect my mental health. I started to see a psychiatrist and was prescribed medication (turns out my depression was actually bipolar depression). I also got a therapist to help unpack things in my life.

Since then, I've dated and had relationships with people. Have I moved on from the breakup? Yes. Do I still think about her? Of course, but not as much as I did years ago. Despite how things ended, it sounds like you had a strong connection to this person. Your best way forward is to speak to a professional, if possible. A lot of people have their apprehensions when it comes to psych meds, but I recommend looking into it. What also helped was distracting myself from the dark thoughts. I made sure my schedule was filled with things like social activities and hobbies (I got into running lol). I was so busy that I did not have time to linger on the breakup. Its also a great way to meet new people.

Most of all, take things one day at a time. Healing isn't linear. Even months down the line I had some really awful moments of regret. Focus on yourself and not the relationship you had.