The answer, Diving Dubai, is simple to state, but work to do. Practice, practice, practice. Practice the skill as often as you can. It is an important skill to master, and mastery comes through repetition. You difficulty may be technique related, not just a mental block. When mask clearing is done properly it is much easier than your experience has been, and the mental block goes away. Remember to look up. Remeber to not hold the mask away from your face, your will let the water back in the moment you stop breathing out through your nose. There are other common errors, but mask clearing is a very individualized thing. Consider reviewing your video on the subject or even joining in a class that is working on the skill. If you have a good relationship with a local dive center, they should let you do that without charge.
Divemaster
Divemaster