Refused blue badge

I'm 70 yrs old. I live in Preston  I  took retirement at 54 because I was in so much pain. This was diagnosed as fibromyalgia.  Over the years it's got worse. Now I can hardly walk, I applied and was granted top rate attendance allowance. My husband was credited with carers crefit.  I have applied for  a Blue badge but have been refused. When I question it they saI'd that I could walk. Otherwise I'd be bedridden. I insist I can't walk far. I'm not very good at explaining myself. If I can't get out I'm just getting more disabled.  The doctor insists I must move a little every  day. I have a vitamin D deficiency so need to get out.Even if I had a BB I couldn't go around shopping etc but it would help me get to doctors hospital etc. I don't understand why AA isn't treated the same as Pip and DLA. Sorry to go on.