disappointed

I am so not in a good mood today. Many things disturb me emotionally.
I am very disappointed with myself. Why couldn't i say NO, just NO when i should have said it? Why do i think so much for others when they never even bother to care what i feel... I am so sad. Partly because of people around me, and partly because of myself.
May be i am too much in holding onto my principle " Let us serve, not to be served".
I just feel that i serve inappropriately, not-supposedly, too much.
As the consequences, i am the one who finally suffer. These are the examples
~~ unexpected expensive dinner~~
I try my best to stick onto my budget. I try not to eat out very frequently and instead just cook myself. But somehow, some plan come out of nowhere, without a proper discussion, with no expectation of the price that it will cost. I dun like to be involved in a plan in which i never asked to discuss about. I just hope that people will consider more about others. Please do something that everyone agrees with. Some are just not as lucky as you are. Just because of your action, other suffers.
~~unexpected pay for helping people~~
I helped to copy books and take orders. I had to pay for the extra when the other didnt even bother to say sorry or pay for it. I was trying to help others, but finally i suffered. It was like, ain't it better if i didn't initiate the help at the first place?
~~ extra shares for a gift~~
We were sharing a gift. All were agreed to share. Indeed that person voluntarily to join. I paid first. But at last, i had to pay for 2 person shares including mine. Because the one who volunteer didn't bother to ask about it.
~~and many many more~~
Like they borrowed money from me. But never bother to remember that they actually owe someone money and eventually they just forgot about it.
I dun give a damn about the amount of money. But is not it our responsibility to pay back for what we have borrowed? Sometimes we take it for granted, thinking that "mm.. it is just of little money, she won't mind about it"
or
"i'll just pay at other time la, she is not in need of money also.."
Yes, this is the thoughts that come from those who never suffered financially.
I have experienced it. To me, every cents count. May be RM 1 is nothing to you, you can lose it and said it is just RM 1 after all.. But not for me.
I depend 90% on my Petronas scholarship, which is JUST enough for me to survive. I don't ask money from my dad as u all do. I only ask him if i am extremely desperate.
I am not born with silver spoon.
I experienced having just RM50 for like 2 weeks. And i value every cents i have during the financial constraint. I strictly stick to my budget in which i didnt eat out, i just cooked. And i survived!
But there are people out there who are spoon-fed since they were born, never know how it feels to have no money. They have a lot of money, but when it comes to pay the debt, they can simply forget about it, without knowing that if they pay, the person need not to tie their belt tightly on the waist.
I really wish that people would become more and more considering about others.
Even in trivial matters. It is the little thing that you do, counts. This has been my principle all this while.