I can totally see why you are feeling so low. Going through redundancy, losing your home and having a baby are all very stressful abs you've had all 3 quite close together.
Does your DH know how you feel? I'd start by telling him, if you can.
I'd start by speaking to the PANDAS Foundation about how you are feeling. They are open until 10pm tonight although the earlier you call the better chance you've got of speaking to someone.
Then in the morning I'd book a double appointment with the GP, if they ask if it's an emergency, yes it is.
Tell the GP how your DC1 is behaving abs ask for a referral for him to be assessed for ADHD/ASD, just to get those ruled out.
Also tell the GP how isolated you are and how much you're crying. The GP might offer talking therapy or ADs or both. What they won't do is report you to SS.
Take your DH along to appointment with the or have him on the call if you can. It's a sad fact that most GPS listen more and are less dismissive if Dad is there too.
While you are waiting for the referral try Toddler Taming with DC1.
Once you've got yourself in a better place you can think about applying for the free childcare that DC1 will be entitled to after his 3rd birthday, doing that house swap abs maybe going back to work and sanding a deposit for a rental closer to where you want to be 