you seem to have a clear understanding of whats wrong and may get more help by contacting the psychiatric ward of a hospital
contact charities, explain your situation and ask for help,financial assistance and someone to go with you to doctor or hospital would probably be a help
tell doc you have no money as they often give out free meds, sample packs, starter packs, etc
it will help a bit if you relax your muscles and breathe deep and slow
toprol being a beta blocker also reduces the physical problems from anxiety
I'm sorry that you are having such a hard time right now but you my think about calling Health and Social Services for help as they can help with paying for your pdoc as well as your meds and can help you with your rent payments based on your income and can help you get your child support But you need to just put your anxiety aside for both you and your kid and think about your health and well being for your family.