Well sized bumps forming on forehead, not a cysts or pimple.

[Bgouldy]

So about a year ago I got this well sized bump on my forehead, I didn't know what it was so assuming it was a pimple I tried to pop it but all that came out was clear liquid, blood and occasionally puss. Its not a pimple or a blackhead or a cysts because it goes away over time. So i tried draining it by squeezing it but then he quickly scared. A week later my face was full of scars and bumps so I went t my doctor and she said it was impetigo. I was treated and it quickly cleared up but it came back slowly, I've tried going on specific diets to figure out what causes it but never found out. Even if it does go down by squeezing it,it fills back and scars. I just want to know what the hell it is and why its on my face. If i had to compare it to something it looks like a mosquito bite but more movable and acne like. Now my acne has cleared up and its just these bumps and ive tried looking on the internet but ive found nothing. Please someone tell me or find out what this is, thank you.

[purple1234567]

Is it just one bump or several?  Impetigo usually isn't just one bump- have you been back to another doctor for a second opinion since it returned?