This sounds very hard. I can reassure you that many first time mums I have known will privately admit to being utterly terrified there is something wrong with the baby. I definitely had moments when I thought the anxiety and responsibility might overwhelm me.
Also - Bad dreams are really common in late stages of pregnancy - it’s not a time when sleep is easy.
Maybe like me you envisaged this glowy, carefree stage of pregnancy when you’re excited about meeting the baby and everything is simply wonderful. The reality is often really different.
A couple of things strike me positively: you are really self-aware - you understand what is triggering you, and how that is impacting you. You know that some previous coping strategies aren’t appropriate when you’re pregnant.
There’s no single magic solution but I’m confident it’s in your power to help your mh improve.
You need a new way of reacting when you have those horrible memories or fears. Recognise them for what they are: your brain is trying to warn you about a danger, but the danger is not necessarily something that is going to happen now. It’s very unpleasant to experience those feelings, but in the end it’s unlikely these horrible things you are worrying about will happen now.
The way I handled the anxiety was to spot when it was happening and do something about it. If I woke up in the night I’d get up, put on a low light and make a drink of warm milk. I might listen to some music or read an amusing book for a little bit until I felt calm and ready to try and sleep again.
In the daytime I followed the advice of a hypnobirthing book that someone gave me. It seemed quite silly (I am a practical person) but I gave it a chance - lots of positive affirmation mantras and visualisation of good outcomes, breathing exercises, stretching, walking in fresh air, making a nice playlist to listen to while I did these tasks - associating the music with relaxing became really helpful as I taught my brain to associate the music with being in better frame of mind. Doing something active or practical to distract myself helped a lot too - cook a batch of pasta sauce, or tidy out a cupboard or call a friend for a chat.
I also enjoyed watching quiz shows, comedies and romcoms - found that just having somethin amusing playing in the background was really helpful so it wasn’t just me and my scary thoughts.
Getting your mind out of spiralling down, that’s the trick. And different things may work on different days, and you’ll find the things that work best.
Some of these things also work quite well if you have a bit of PND too (especially the walking and distractions).
The most important thing to remember is that you will be a great mum. You’ll make little mistakes but you’ll be fine in the end and so will your baby.