Hard lump in breast. Swelling with pain?

2 months ago suddenly I feel shortness of breath and breast heaviness  , then I see lump in my left  breast lobules  that time it's was round but within 1-2 weeks it was hard and big then back pain , then I go to checkup doctor do usg but it's normal usg not detected anything my breast was very heavy that's why I think, lung x ray normal doctor gives medicine but no relief now my left breast tissue are to tight and , I feel left armpit swelling and tightness and too much pain in arm . New pain started in  left breast pinching like near armpit from 3 weeks I don't feel my breast normal I feel something wrong I got all symptoms of metastatic breast cancer . Please tell what I do cause I have heavy breast ? Usg not detected lumps .Can I have metastatic breast cancer?  and I also feel  shortness of breath and arm numbness and swelling with pain ?