How do I prove I do not have trust issues?

My fiance relocated out of town for work, I will soon follow with moving truck. We get along great,everything in common. Something rare in past relationships. I calmly asked him if anything was going on between him and a co worker he texts/calls all the time for hours, even not at work, blowing me and others off while he's on the call, or puts me on hold. I'm not a jealous person in relationships, he's known me since teens. When I visited they texted constantly. She's 15 years younger than him married with kids, barely out of high school/college. He flipped asked how I'd feel if asked the same. I said, it depends how asked and I believe in talking things out. He said I was jealous like his exes,gave the silent treatment for 3 weeks not saying much. His friends said he treated his exes bad, n had issues. He hid it well. He always seemed chill, nice n upbeat. He's blowing it out of proportion. He's not considering the distance I have to drive soon. He said I shouldn't need "reassurance". Am I in the wrong?Thanks.

No I def don't want to be second choice. I even mentioned it and he was like you are not. But I don't know how to prove or explain I do not have trust issues. He's known me for years and knows I was never like that with anyone in the past. But since I asked him that question, all he dies us compare me to his supposed crazy exes who screamed and yelled at him all the time. And he said I hurt him.. I am never like that and I wasn't, I was calm and I think given the circumstances anyone would ask the same. It's not like I'm there. Maybe his exes weren't crazy. He has given me the silent treatment for 3 weeks. He's done that before with silent treatments. Seemed out of his character. Seems something narcissists or abusers do. He even has his mom and sister mad at me. Not sure what scenario he told them. It should of been a simple convo, normal ppl have. A yes or no question if there was anything I should be worried about. I can see a person getting upset if a person always acts like that and is mean and accusing. But he thinks I'm going to be like his "exes".

I hate to tell you this, but there is definitely something going on with that woman. A) It's not normal to be talking to someone that much, even if they were just friends, especially since you mentioned he blows you and other people off in order to talk to her. And B) The fact that he got so defensive when you questioned him about it is a huge red flag to me. If he was really concerned about you and your feelings he should have had no problem sitting down with you and talking this out to make sure you were comfortable. I obviously don't know for certain, but it just sounds to me like you should trust your instincts on this.