Another one of the low self esteem signs: Instead of expressing your feelings you suppress them. Often times people with low self-esteem issues keep busy so that they don't have to deal with feelings that they don't want to experience. This low self esteem sign is very evident because you can see it immediately on the outside.

By always being busy you don't have to look at your underlying self esteem issues and challenges.
There are some good exercises that mildly force you to take a look at your feelings with the purpose to change the underlying issues of low self esteem.
Decide that what you say is worthwile and you don't have to count this low self esteem sign to yourself.

Wake up on time
Learn meditation
Meditation and mindfulness in clinical practice