I think I might have played a part in our break up

My ex (together 3 months) was going through some difficult issues and I hadn't seen him in 3 weeks so I messaged him asking how he was doing. He said he was sad and he didn't want his chaos to be my chaos. My birthday was last Tuesday and he sent me a text saying happy birthday beautiful. The next day I noticed he completely blocked me on all social media and I'm pretty sure he blocked my phone number. Also, my friend said she saw him on a dating website and he mentioned something about wanting to take things slow. When we first got together he had disappeared for a couple of days and eventually got back to me stating he had very cold feet and he was very afraid of getting hurt. He had mentioned to me that he wasn't even looking for a relationship and then he found me and I was perfect in his mind. He mentioned that he would of always regretted not trying with me. Also, in my opinion I don't think he was over his ex. I gave him a second chance and he really tried to make it up to me. He even asked for me to be his girlfriend. Now, he has just disappeared. I guess it's my fault in a way because I let him back in a second time. Do you think he left because he wasn't ready for a relationship? Another thing that has been bothering me.. he had grown distant 3 weeks ago right after I had asked him if he wanted to break up because he wasn't really making time for me. We had seen each other for a couple of hours in two weeks. He responded that he knew this question was coming and he did not want to break up and he had no complaints. He said it was up to me to break up. I told him I didn't want to and I just really missed him. I keep beating myself up thinking I caused this because maybe he was fearful I was going to break up with him. It was stupid of me to ask that question. He does have trust and fear issues. Do you think I caused this? I can't even ask him about this because he's ignoring me. The main question I have is if you think this was mostly my doing. Thanks!

If he isn't bothering to talk for over some days without reason, if he doesn't communicate his feelings
I don't see why you'd bother anyways