I feel like we are so stuck in a place where people are too scared to tell one another that they like each other. We all need to get out of our heads and just go for it!
1. What are you waiting for?
What is the point of waiting around. You obviously know that you like this person so why wait any longer to be with them?
2. Remember that everyone messes up
If the person you like does something that makes you mad, if you really care about them, it shouldn't be detrimental. We are talking about service level stuff.
3. If you aren't exclusive, you can't get mad
Until you and this person are officially talking (and both parties are on board), the person you like can do whatever. So if you don't want to keep getting hurt watching them do whatever then establish something. At least tell them you want to be with them then tell them.
4. Don't overthink it
It's really not that deep. You aren't putting a ring on their finger so you might as well go for it. I can get in my head a lot and talk my self out of talking to someone. Go for it and have fun. Don't take life too seriously.
5. You have nothing to lose
So you tell the person and they say, "No thanks." Oh well? Brush it off and move on. You now get to move forward with your life and find someone who likes you just as much as you like them.