people around you might be more sensitive about this issue. Just be more self conscious in order to realize how much people around you suffer from your whining and how often you do it! Do understand that complaint and whining are two different things. You complain when you calmly elaborate about how something is unacceptable and how it should change. However, whining is a totally different scenario.
Boasting might gives us great happiness, boost the ego for a bit, but actually tends to be quite detrimental for our social life. However, nobody prefers to be in the company of a boaster and it often leaves a bad impression on the people you socialize with. Only if you are a comedian and are boasting for fun, then it is surely to be taken in a light hearted manner.
However, you also need to have a distinction between honesty and boasting. If you are honestly telling others about your achievements, then there is no need for you to hide them. Rather, if you actually feel like telling others about something, then that is supposed to be boasting.
So evaluate yourself on these parameters and try to judge yourself about where you go wrong while socializing with people. Correct yourself and use these tips so as to properly interact with people and move towards a positive personal change.