Severe Back Pain On Deep Breathing, Head Movements. Have Nausea. Treated For Painful Lump In The Breast

I have serious pain in My back between my shoulder blades, it hurts when I deep breath, relax move my head, tense up ect i can be sitting still and will get a tringe of real pain. Feels like something may need to be cracked back into place. I feel a whooshing sensation to my head and face and feel a bit nauseous This happened a couple of weeks ago but I put it down to maybe sleeping funny, it calmed down the day after. Now it has started again only this time it was half way through the day. I m a 31 year old female and I do have 2 young children. I do not recall any knocks, bangs or even pulling it. I went to my go when this pain started as i i had a big painful lump in my left breast ( git antibiotics for) didnt mention the back pain as i said before, I thought I had slept funny. Please can someone help me