Having reported historical sexual abuse when you were a child, and with the court case pending, it's no wonder you're feeling depressed and seeing your abuser and his family strolling around your town when you're out and about is bound to cause anxiety, especially as you've said you're terrified of them. No wonder you've taken to staying in and it's hard for you to walk to the corner shop some days.
Have you been in touch with Victim Supoort? They should be able to help with some of your anxiety and I suggest you also consider getting in touch with Rape Crisis.
I would caution against engaging in any counselling sessions before the court case as I'm aware that victims of sexual assault are very often told not to seek counselling until after court cases have ended and I wouldn't want anything untoward to happen to the case at this late stage.
However, you might want to seek your police liaison officer/case worker's advice on that particular aspect and it certainly won't hurt the case if you feel able to confide in your Health Visitor or offload to a listening service such as the Samaritans.
Do you have a date for the court case and will it be before or after the birth of your second child?
On a practical note, use online shopping delivered direct to your home for food and other necessities or ask your dp to shop for you. If you have a nearby park with play area for your ds perhaps you could try to use it when there are unlikely to be others around, or wait until your dp is off work so that you can go as a family.
The myriad emotions you're experiencing are normal and I doubt that there is anything wrong with your mental health that won't begin to resolve itself once the court case is over.
Please consider reporting your post and ask mumsnet to move it to the Relationships board. Although you might not consider it to be a 'Relationships' issue, there is a lot more traffic on that board and you will find many responders who will be willing to hold your hand throughout the birth of your second dc and the court case.
Some of those responders will, unfortunately, have shared your experience of childhood abuse and will understand exactly where you're coming from and the impact it's having on you now.
In addition, moving your thread from this time limited board will enable you to look back on it at some future date to see just far you've come on this difficult journey.
You've been very brave, OP, and I salute your courage 