Feeling Scared and Confused in My Relationship

Have you read into attachment theory? It's not uncommon for people with avoidant or fearful-avoidant attachments to feel the urge to run when things get serious. Perhaps it's this?

i understand what you're going through. i still sometimes get those thoughts even though he's wonderful. it's the anxiety and trauma that's making you feel this way and making these thoughts worse. self sabotage to keep you safe. but if you're aware that he's keeping you safe, then keep pushing through. the thoughts do get easier. it's also good to follow up with thoughts such as "he makes me laugh, i like being around him regardless of these scary thoughts, he makes me feel better, he'll understand" i promise it gets easier, take care! you deserve good things

It's valid to be afraid and have second thoughts, we're human, not machines. You love him and as long as it's a healthy relationship, stay with him. If one day your heart isn't, then at that time it's time to call it. But yall see a future together, that in itself says a lot about your love (positively).