Why did she stop keeping touch? Did I make a mistake and should I be glad?

There was this girl I used to work with about year ago. We eventually started talking outside of work ( just texting and calling). I knew she had a boyfriend and a kid but I still developed feelings.
I ended up telling her I had feelings and she told me she did too and that’s why she started texting me, but that she had to look past it and just wanted to be friends cause she had a boyfriend and a kid. That really hurt. I didn’t know what to think. I felt hurt and I didn’t want to be just friends. I couldn’t look past it but we worked together so I had to. I should also mention that when ever we stopped talking she would block me and then unblock me when she wanted to talk. Fast forward she ended up quitting and found a job somewhere else. Even after that she would call me once a week some times more sometimes she’d skip a week but she’d call to see how I was doing and how things were going where I worked. I was still blocked and at this point I thought she was calling just to be nice and I always liked talking to her but I didn’t like how I could never reach out to her. This kept up for about 9 months after she quit. About a month ago she called and I missed her call cause I was at work. I was blocked so I couldn’t message her but I knew I saw her on my contacts list on my WhatsApp a while back so I tried messaging her there saying that I missed her call sorry. She received and saw the message. She ended up calling me a few minutes after. We talked for a bit and I asked her about the blocking situation. I asked her if she would ever unblock me. She said no that she’d rather keep it this way. I asked her why and she said she doesn’t really talk to other guys. I said I get cause she has a boyfriend. She ended saying that she would reach out to me. I ended deleting the what’s app convo. On what’s app you have the option to delete the conversation for everyone which I did cause I figured she’d do the same thing. I don’t if she thought this was messed up. But since I missed her call and asked her about the whole blocking thing I haven’t heard from since. Was she hurt that I missed her call or did she get mad when I asked about the blocking thing? I miss our conversations but I also feel like this is for the best. Should I message her on what’s app cause she didn’t block me on there? Or should I let her reach out to me if she ever wants to. I will say to I was an over thinker and she told me this and I feel I was also an overtexter when we would talk. This may have been another reason why she may kept me blocked.