Congratulations!!! I too was feeling exactly the same at almost this time last year. Something was nagging at me and dh and I had said we have one of each we are happy but deep down I did want another one! I know he said ok because of my desire but was still supportive when we fell pregnant a lot sooner than anticipated! Said we would wait until the end of the year to start trying again but mother nature had other ideas!
I am sitting here with our 9 week old son and couldn't imagine life without our third bubba now! I don't work and we have a car and house loan but we make do! It can sometimes be stressful and we go without the luxuries however those kids are what make it all worth it!
It's only natural to feel the way you are feeling and I did feel that way throughout the whole pregnancy and wondered if I was a horrible person but it did pass as soon as I held him!
We have everything we need baby wise and he received lots of lovely new pressies so it hasn't been financially challenging just yet. Things will be when he gets bigger but by then hopefully I am back working!
By the way I have a 4 yr old and 2 year old also! It's mentally draining but if you have the right support it's manageable ;-))