Love my boyfriend but miss my ex

Hi everyone I seem to be struggling with this lately. My ex and I broke up about a year ago, he broke up with me because he was no longer interested after dating for two years. We had gone no contact for almost that full year and I slowly got over him. I met my new boyfriend during that time and I love him and I know he loves me and everything is going great with him. The only thing is that recently my ex texted me to catch up and apologize and ask if we could talk and it made me realize that I do miss him. I’m feeling super guilty because I love my boyfriend but I’m also thinking about this other guy too. I feel horrible about it trust me no need to tell me, I just need advice on how to handle this. I’m having a really hard time and I don’t have access to my therapist this month /: