That's a really good question! But you answered it yourself. 

When you're stressing about not being in a high vibration, you are putting negative energies around you so you're automatically in a low vibration! You attract it!

Instead you have to tell yourself that you are in a high vibration! And you will!!!
Just repeat it until you feel it! Then read success stories, or do something that makes you happy!

And bingo!  

It's a process. You will get better with time. And some day, you will wonder what reason you ever had to feel bad. I mean, you are the creator of your reality. Nothing can happen to you, everything happens through you. There can't possibly anything bad happen to you without you inviting it.

Your feelings are your guiding system. So it doesn't help to change the feeling. It only shows you where your thoughts are in relationship to what your Inner Being is thinking about the same topic. Change your thoughts and you will automatically feel better.

It's Abraham terminology. They say that the moment a desire is born within you, your Inner Being focuses fully on the desired reality and becomes it, lives it in the now. If you are doing the same, your frequency and the frequency of your Inner Being are a perfect match and you feel wonderful. But if you are looking in the opposite direction the frequencies are dissonant and you can notice this dissonance, because it makes you feel bad.

Thank you so much!!!
Today, I told myself often that I am in a high vibration and I meditated for 15 minutes.

In the afternoon my specific person contacted me out of the blue! Sooo happy!