The terrible fives?

Okay!! I have heard and experienced the terrible two's but what is going on here? Haylee has been going through something new. I must say it did begin before she was 5 but seems to be getting worse and I have no idea what to do. This is what this mornings scenario was like. Haylee had preschool at 9. I got her up at 8:00 as to give her enough time to get going this morning as she has a hard time beginning each day. So, she is in charge of bringing the snack today. But, the snack that I bought is not what she wants to bring. She wants to bring something else. She doesn't think her friends will like crackers and cheese. WHAT? She wants to bring donuts. So that begins the first meltdown of the morning. The next one comes when she does not like how I have done her hair. This is a constant fight with her. She would rather just have her hair down in her face looking like an orphan child. So, she goes in the bathroom takes out the braids and ponytail, gets her head all wet with water and brushes it straight. By this time it is five past 9:00. My patience are now gone... We are late to school and my child is crying in the bathroom saying "my mom doesn't even care about me." AHHH! The last meltdown was because her belt which was tied in a bow, was to bulky and could be seen under her shirt and she wanted me to retie it. So, I tied in in a knot so you couldn't see it under her shirt and that was TERRIBLE.... (in her words) I want it in a bow. So, I bonked her on the head, took off the belt and put her in the car.. We were 20 minutes late for preschool and I sent her there with red puffy eyes from crying about how mean I am... But, I did try and tell her that I loved her and feel bad that I didn't handle it better... But, what am I to do?