Congrats - and yes I think it is normal to have a little bit of worry/panic.
We were ttc and when I got a bfp just 2.5 months after coil was removed, I thought 'oh crap' When hideous sickness kicked in - I thought 'I can't do this'. I now realise how lucky we are as many friends ttc for way longer than that. At 35w I am just desperate excited for baby to come now.
A friend of mine was ttc - and when she got her bfp - she sat in the bathroom and cried for an hour out of sheer panic.
So yes you are not alone in the worry thing - infact I would say when the reality of having a little bundle that will 100% be reliant on you kicks in, it's almost a positive thing for you to feel apprehensive, because it's a big deal to take seriously. We (women) also feel this apprehension during PG - because they baby is reliant on us at that point and as you start to 'feel' PG it's all to clear to us, our partners feel the whole 'panic' thing a little later (IME).
My DH is now in a flap trying to get the nursery ready, even though I have nagged him for months about it, he is just now getting into his head that in (potentially less than) 5 weeks there will be a baby here.
(My DD was 5 when I met my DH and so although he is already a great dad (she's nearly 12 and he is the best ever), he's never had the reality of a baby hit home yet :))
As for the cost...you cope with what you have. With DD I had NO money nothing, we survived, we did second hand or gifts/donations, it was okay. This time we have a little more to spare, I still haven't gone crazy spending money, as I KNEW there was no need to. A new baby needs a comfy warm safe place to sleep, nappies, babygrows, milk (remember your BM is free...so you can say a boob there :)) and a whole lot of love and cuddles. Those things don't cost much.
Check out, gumtree and freecycle online for second hand stuff (in fact I think mumsnet has a sales board too you can look up)
I also found the nearly new sales to be fantastic (I have been to an NCT one and a Jack and Jills Market one) got some great bargins from parents that are just trying to sell what they don't need anymore to afford the next things their children need - I'm all for us parents helping each other out in this way.
Congrats again x