How To Remove Itching Pimples On Chest/back/face?

hello i am 19 yrs old and i had been on birth control i stopped taking them 4 months ago and i stopped having a menstrual cycle until this past month and about 5 or 6 weeks ago i started to get pimples all over my chest area and my back and my face there are many of them and they look like they are under the surface bumps and they itch i have tried everything to get rid of them and i don't know what to do