Hope- but not too much

I am having a really tough time with holding onto hope. I am hopeful that God will provide a child for us. I am hopeful that our doctor knows what he is doing and will do all that he can to make IUI work for us. But I also fall into so much joy and excitment that I get afraid that i will disappointed. How do you do that? How do I get excited that FINALLY we have answers... FINALLY we have a procedure.... and yet I dont want fall into sorrow again if this doesnt work. Does anyone else feel like this? Overwhelmed- loads of overwhelmed-ness!