Worried about lung cancer at 28??

For the past 6 months iv been experiencing breathlessness, even doing basic things such as changing bedding or walking to the shop, at first i thought nothing of it as i felt ill snotty noes and generally weak and thought maybe i might have a chest infection went to the doctors chest sounded clear she done a full blood count all come back normal. Now i am having really bad back pain started in the shoulder blades and now travelling down my spine. Iv got 3 young children youngest only 5 months old so i am a panicky mess at the moment im going to make another appointment monday and request a scan. Im sure its something and nothing, but my sysmtoms arent imroving. Just needed to tell someone