From good to bad in 10 minutes

So I have the most amazing boyfriends now. His name is Zac and he is my everything. I love him with ever piece of my heart and everything i own. Since my little brother moved away, Will, my little brothers best friend became new brother. Zacthinks that I am giving him a lot of attention and that makes him wonder. He said my friend saw me at Subway holding hands with some guy. No. Never would I do such a thing. I really.....i can't believe that he would even think about anything like that. He doesn't like that I give Will so much attention...it is just because that my little brother is gone Will is my Brother now, but if he doesn't like it then I will stop. I'm also just really hurt that Zac would think of stuff like that. It breaks my heart even more when i start to think about it. My day was good today, but now i just can't stop crying and aching over this situation with him. I don't know what to do. I just hope Zach believes me that he is everything I have ever wanted. I just hope he will stay with me. I love him and would never do anything to ever hurt him. Like ever.