No issue dear.
After looking at your profile I can safely say that your Hidden MMR is 3600-3800. That is why you keep on changing your skill bracket from High Skill bracket to Very High Skill Bracket and vie versa.
If you play now you can get MMR of around 4000. But if you want to increase it, I would suggest you to start playing calibration after all your matches are in Very high skill for at least 20 consecutive matches. Even if 1 match comes in High skill in these 20 matches, dont play calibration.