Thank you for that information, and I appreciate how difficult this is.
You obviously need to prepare for the first hearing, and file a response to the C100 application.
You can file the C7 acknowledgement form to indicate that you have received the application and don't agree to this. Along with this, a C1a form detailing the allegations of harm that you have set out briefly above.
You can then file in response, with a C2 application form, an application for a prohibited steps order to be heard at the first hearing. This would be an order that your son is not removed from your care without the permission of the court - just to protect you both in the interim.
You will need to write a witness statement to support this application.
In this statement you detail both the history and the response to the application, also detailing the lack of contact, lack of support/ interest and your son's special needs and how this affects him.
You can say that you do not support contact at this stage but if the court did decide it was in your son's best interests that you could not be present and that you would insist that it is professionally supervised. You could also ask that before he is awarded any contact at all that he has to undertake specific work with either Cafcass or social services to understand how to parent a child with your son's specific needs.
If contact is on the cards, in my view it is really some way off in time.
The forms you need are all on the www.gov.uk website - simply type the form reference into the search engine and the form appears along with (usually) a guide to completing it.
I hope that this answers your question?
Can I clarify anything further for you today?