what's going on!! 😢

I keep having this feeling that my husband is losing interest in me. we have been married 5 years. we haven't had really any issues until here recently. he has lately been distant and even turns me down when I want sex. I'm becoming sexually and emotionally frustrated by all of this! he has never been a touchy Feely guy nor does he say I love you very much. but her lately he won't touch me, he won't kiss me like he used to and he doesn't talk to me hardly anymore. he talks to his coworkers more than me. he has gotten really close to a female coworker and I've expressed that I was concerned about it. but when I asked him to slow it down all he does is text her now and occasionally he asks her to go to dinner with him because I'm not home for working 2 jobs. she is also married as well. I'm not saying he's cheating but I'm worried he has gotten emotionally attached to her and is starting to like her. he's not a bad person but I'm just getting worried that this coworker could be ruining our marriage. I understand don't take work home with you (as far as being angry) but at least talk to me about your day and what happened. if he mentions it, it's not very much and he's done on to something else. I'm just tired of stressing and worrying about this. I need serious advice.