Guilty about wanting a second baby

Laura • I am 28 years old and my husband and I had our first baby in August 2016! Baby number 2 is on the way!!
My son is now 1 year old and is the best thing in my life. My husband and I had to go through <a href="">IVF</a> treatments to have our son. Now that our son is 1 we have been talking about having a second baby. I have been having a lot of guilt when I think about it. I feel like it would be unfair to my son to not give him all my attention but we still don't want him to be an only child. Having to go through <a href="">IVF</a> treatments makes it worse to me because we have to make an actual decision on having another baby. It's not like it will just happen on its own. If anyone has any advice on how to get past this or has felt like this before, I'd love to hear it!