Sorry to hear you are having such a difficult time.  I would talk to your Dr about increasing your anxiety meds.  An increase in anti depressants will take a while to have an effect though.  It's also possible you might be prescribed a v limited supply of something like Lorazepam for acute symptoms .

Id highly recommend CBT .  It's available on the NHS via your GP but waiting lists can be long.  Obviously quicker to see someone privately - if you can afford it of course ...

I've found distraction quite useful - eg meeting friends and doing a jigsaw can be quite calming.  Exercise is also helpful.

Remember, most mammograms show no evidence of cancer.  Also even if a lump is detected most will not e cancerous and instead will be a cyst etc 

Hope that helps