Waiting

I have a hard time waiting/relying on people it seems. If I need to be somewhere, I have a hard time waiting for people who say they will come with me. If someone says they will do something for me, I have a hard time relying on them. Maybe its the trust thing, I don't know.
Someone told me today they would do something for me. I really needed it done, but they put it off. It didn't get done tonight. It makes me upset, but I shouldn't be upset. It is my fault for relying on them to get it done. I should have had an alternate plan. Maybe I am more upset with myself.
If I don't rely on anyone, then I don't get disappointed or hurt. Maybe that is what is wrong with me. Even in a relationship, I try not to rely on the other person. One, I don't want to be a burden and Two, I don't want to be disappointed. If one has no expectations there is no disappointment. But ultimately there usually is. I don't know why that is. I mean there are certain expectations in a relationship. Like treat each other with kindness, pay attention to one another, be faithful, etc. So where does the disappointment come in? I think it is a break down of communication. One does not express their needs or one does not see/hear/feel what the other is saying in said expressed needs. Or maybe there is a conflict in those needs. And how much does one give while the other takes without giving back before the disappointment sets in? While there may be more happiness in giving than receiving, it is nice to be on the receiving end once in a while.
Or maybe while on gives in the only way they know how but the partner does not see it as giving, then what?

I am afraid to ask for help. I think it is so because then I have to rely on someone else. What if I am a disappointment to that person because I have to ask for help? or what if I am disappointed? I don't know if the risk is worth it at times so I keep quiet.
If I fail, it is on me. I have no one else to blame.