He brings anxiety

So my ex dumped me about 2 months ago. He said he needed time to work on himself. He said it would be a break but he told me later that it wasnt just a break anymore. I know he loved and cared for me. He still messages like once a week. He will ask how I'm doing or ask about something he saw on my snapchat story. Everytime I see I have a message from him I get horrible anxiety. I think it's because I still miss him so much and wish it would be a message asking for me back. I'm just wondering if theres anything I can do to make sure I dont get anxious when he messages me? Or if blocking him would be the right thing?