Hi need, welcome, you'll find lots of understanding and support here.
The way you're feeling is exactally how I've been feeling about this pregnancy. I've got a 3 year old too, with dd I fell pregnant within 3 months of coming off the pill and had a very easy and straight forward pregnancy. Just ended up with an elcs as she was breech. When we felt we were ready for dc2, I fell pregnant right away, but mc at around 5 weeks. Fell pregnant again in the wtf cycle and have now made it to 24+1.
For me this pregnancy hasn't felt 'normal' in the way it did with dd and I wasn't particually anxious when I was pregnant with her. It was rare for me to worry about anything, this time it's been rare for me not to be worried on some level. Although I still get worried, I find now it comes in waves rather than being constant.
I can also relate to the guilt. With dd I was so excited from the moment I found out. We told my parents at around 7 weeks as I was struggling with morning sickness. Mil was told at 14 weeks. We've only just started to tell wider family and some friend in the last couple of weeks. Personally I just haven't been ready for other people's excitment, dh has told people with the added on but we don't want to talk about it constantly. In one of the previous threads when I asked about this a few useful phrases we could use when telling people to avoid their over excitment.
Things have got better from about 15 weeks, since I started to feel bump regually move. We found out we're having a boy this time, which really helped with feeling more of a bond or attachement. We didn't feel the need to find out with ddm I throught I'd find it difficult to buy things, but have found it comforting to buy a few bits that are his and making some things for him.
I found it very sereal to have a appointment to record birth choices at the hospital last week. But it does feel like this will actually happen now.