That’s really brave of you to end things. You’re right in that there is a certain pressure. People tend to ask “why” when a break up ends. Like they expect some kind of scandal. I’m pleased you feel better for ending the relationship and hope that the other areas of your life do get better for you xI had to tell him that I was having doubts about our future together because it ended up manifesting in physical anxiety for me (anxiety attacks which would build up all day and accumulate in a panic attack each evening, literally for weeks it was awful) and I obviously couldn't hide that from him. We thought it could just be from spending 24/7 together through lockdown so he went back to his parent's house and we had a 'break' although still spoke most days. Essentially, I felt relieved when he was gone and didn't miss him much even after a few weeks but still had anxiety about being in the relationship. I had to break up with him over facetime as his parent's house is over 2 hours away. I felt awful that I couldn't do it in person but the strain on my mental health was just too much to wait. I basically just explained that the anxiety I had was telling me it wasn't right, even though I couldn't pinpoint a specific reason why which was hard for him. I also told him that he deserved someone who was 100% sure of their feelings and that couldn't be me, and that it genuinely was me - not him, as cliche as that sounds. I think being honest is the only way to go or you risk hurting him more if he finds out you told someone else the real reason or whatever.
We spoke on/off for about a week after but I had to ask to go no contact in the end as texting each other was more of a habit that needed breaking - I knew I didn't want to get back together and didn't want to give him false hope. Despite being the one doing the dumping I was still a wreck for at least 2 months as he was my first love and I felt so so so guilty for breaking his heart as well as feeling incredibly lonely after having someone with me 24/7 for months. I just didn't realise how much of a stress it was thinking I would be with my first love forever lol I know that sounds stupid but I really felt pressure to stay together because he didn't do anything wrong!
It has been around 9 months now and I'm so glad I made the decision to end things, even though life atm isn't going great for me due to other factors at least I'm not stressing about a relationship