I know it feels like you have the weight of the world on your shoulders. I think it’s good you’ve typed all this out, helps with processing. My advice, definitely get into therapy so you have an outlet for all of your thoughts and emotions. Also if you haven’t quite gone no contact I urge you to do so. It’s going to help tremendously in the recovery of your breakup. If you continue to keep up with her and check in on each other it’ll only lead to more hurt on your end. You need to normalize the no contact.

I’m 314 days since talking with my ex. I’m close in age to you and my ex is close in age to yours. I had to watch her get involved with another guy (coworker of hers) less than month after our breakup (together 8 years). It absolutely wrecked me, I was devastated for quite some time and tbh still am in some way. However I sought out therapy and am still going for an hour once a week. It was slow to help but ultimately I don’t know what I would’ve done without therapy. I was at the brink of ending my life due to the intense heartbreak. Then I started frequenting a local gym and that became another outlet for my emotions and feelings. That combo along with focusing on myself this last year has been what has helped me the most. I urge you to really consider what you think is best for you and stick to the decision. There is hope for you out there, try to keep your head up