Was I in the wrong?

A few months ago I was engaged to my fiancé at the time. At the time all we did was argue and he just kept doing stuff I didn’t like (lie about certain things, smoked even when I asked him not to, etc)

At the time we were looking at apartments, and he wanted to get married before this year ended. Keep in mind, when he proposed we were eighteen and we care currently nineteen. At the time of his proposal we weren’t even together for a year but we both had strong feelings for each other and a deep connection. Anyway, it suddenly hit me that we rushed into things and I started getting anxious about starting my life at that point and with the constant arguing I couldn’t see the marriage ending good. I gave him back the ring and I told him I had every intention to marry him but right now just wasn’t the time. Fast forward two months and he breaks up with me because “ever since I gave back the ring he hast felt the same.” I’m not denying his pain or emotions I’m sure it really hurt but we’ve been through so much and he’s certainly done his fair share of hurting me but I still stuck by his side because I love him, I just felt it was a bit unjustified because he couldn’t forgive me for this, and I asked him multiple times if he still wanted to get married and if he still loved me, he continued to say he did, but I could see him no longer put an effort in the relationship and I could feel his emotions towards me change. I’m just so hurt and confused.