Hi Lorraine,
I am sorry you are going through this
Your options now are to submit a Mandatory Reconsideration request or reapply. You have one month from the date on the decision letter in which to get a MR requested, so you have a bit of time to let the initial feelings settle.
Getting a copy of the assessor's report would be helpful, if you have not already done so. DWP usually send them out fairly promptly on request.
If you decide to ask for an MR but have not received the assessor's report you can ask for the MR and say that you will provide further details when you have seen the report. DWP should then allow you a further 4 weeks to get the information to them.
The MR process is explained in the PIP guide.