No...!!!

No i wont do it...! i wont come..I cant ....I am busy.....No please..!!!!
How many times it has happened that you have found it difficult to say "NO" even though its
the essence of time and you dont have any other option. It happened so many times with me and still I find it extremely difficult to say "No" to my friends in most of the circumstances even if it is genuinely required and it leads me into a quandary state.
I dont know why after saying "No" to somebody I feel guilty and seek for ways to please the guy/gal with any other favour i can do simply to nullify my previous denial. They say I am not mature, I cannot agree more, but I cant help it out.
Probably i think too much about others' feelings and keep their desires above mine but i am no one to judge. I feel really bad if somebody says "No" to me and then i will just try to console myself which is always palliative in nature and thats why when somebody asks me even for a small favour, i am done, i try to put myself in his/her shoes and just consider the disappointment which that person will go through and am forced to say "yes" voluntarily or involuntarily.
I cannot see hopes shattering into pieces only because of my denial since its the hope you cannot give back, the incipient happiness you cannot give back.
They say everything is relative, i agree, and in this theory of relativity I am actually weak at.
They say they remember only good things about frds i say i remember everything though not intentionally.
Everything or anything done to me by anybody has an impact in my life, so good or bad somehow I have to be accountable for it and so I must not look for a scapegoat for the same.
So many times it happens people take ride on you because of this gratuitous attitude of yours but then on the back they say the guy is not pragmatic.
Let them be pragmatic and let me be a fool for them as i care less.
My past six years nomadic life has taught me this lesson : Say "no" upfront rather than keeping it in abeyance. The same may sound rude to the person asking for your presence/help but will surely not play with his/her feelings. Dont allow it to linger for no further reason.
Life goes like this and everytime you cant argue as arguments lead to nothing save harsh feelings.
My true friends can understand my situation whenever I say "No" to them as they understand me better than myself and about the rest do I really care......... ???????