@Rockyslife yes I second @Wise0wl - I asked for support after my third loss and was referred to the bereavement midwife. Had a session with her and basically cried on her for an hour as I talked through my losses. It was very cathartic and she was so lovely. I actually got my surprise BFP a couple of weeks after that appointment and she then supported me through the early phase of this pregnancy too. It was so helpful.
Just be kind to yourself - you have legitimate reasons for feeling so anxious and stressed about it all. And much as we all long for that follow-up bro, I'm kind of glad looking back that mine took a while to come as it was helpful to properly process and grieve that loss before being back in the middle of it all so I can see how hard it would be mentally to oick yourself right up again straight away. I always seem to end up recommending journalling on these things and appreciate it isn't for everyone but it has helped me so much with processing everything and with facing my fears in my current pregnancy. Even if that's not your thing, maybe try to find a thing that works for you that would help you process some of this. Maybe that will simply be finding the right person to talk it all through with.
Finally, and this is said with love! - stop giving yourself this message "I just keep telling myself baby won't have a heart beat and mentally it's going to kill me if that's the case" - this simply isn't true. And I say this having gone through recurring loss last year which I would have never dreamt of going through and if you'd told me at the start of last year what I was going to face I would have equally said it would break me and there's no way I'd come through it ok. The sad truth is, if this is something you end up facing, you find strength you just didn't know you have. It's not strength anyone wants to find, but you do. The chances of being one of those people with more than one loss are very slim. But please know that you will be ok whatever happens. And also, there is still always hope.
The wheels are already set in motion. This little baby you are carrying will either be ok, or they won't. And I know that sounds blunt, but that is the bottom line. And you can go mad focusing on all your worries, or you can try and be in the moment, trusting and hoping, and knowing that whatever will be... You will come through it. I'm still sad about my little ones lost last year, however, the one I'm now carrying wouldn't be here if they had been successful, and I know without a doubt that once they are in my arms, I won't be able to imagine not having them in my life. They are meant. And the others weren't. All shall be well. 💗
Hope that has all come across how I intended it to... Not saying that your worries and fears aren't valid, but trying to help you to see that there is always hope. Even when things are darkest. 💕