HELP!

So I’ve been with my boyfriend for 5.5 years I do love him and we’ve moved out together. But I’ve recently go in contact with a guy from the past and there’s still a spark and I really like talking to him, but I’m with my boyfriend who I love but I don’t know what to do my mind is fucked atm I’ve got shit going on I don’t know what to do. My boyfriend doesn’t know either and I’m suffering with so much anxiety.