This might sound funny and unimportant, but having a good self-motivation is a need. We cant rely on other people to motivate us because they don't give a damn care (almost). We cant rely on motivators that come to our schools or colleges to lift up our inner spirit because all they do is giving theory and that theory might last in your brain for few seconds and gone. We cant blame other people if they give wrong motivation that doesn't suit you because how in the world would they know who you are.
OK, my point is, we understand ourselves more than other people in this planet. Some says our parents understand us more but I don't entirely agree. Parents have different perspectives and emotions, even though they did undergo adolescence, but their adulthood has taken away the feelings and emotions they usually have during teenage years.
We. Ourselves. Us. need to look for the motivation. Its ok to feel sad or to feel guilty, its ok to be angry and to feel hopeless but its not ok if those emotions run inside you forever. Go. find books, watch Oprah, listen to good musics and contemplate for awhile. Let the positivity inside you out and to do that, you have to do it on your own 1st.