Why do I feel demotivated?

Do people around you criticise you a lot? Do people around you think that you are not good at something they are good at? And, because of that do you self-criticise yourself?
Never forget that the bigger critic of yourself is you itself. If you do not motivate yourself, people around you will not motivate you. People around you will also think that if you are criticising yourself, they also can criticise you and talk bad things about you behind your back. This happens because you don’t trust yourself and the capabilities you have. If you start trusting yourself, people around you will trust you.
You might be thinking now, that how can you stop self-criticising yourself? How can you trust yourself with a certain amount of work? There’s a way to do that and that is, to keep small goals for yourself. For example : when you want to read a chapter which has 4 to 5 pages, you can tell yourself that you can read a page of this chapter within 10 minutes or so.