My first 2 were 19 months apart. The next one came when my youngest was 2.5. My next will be born the same month my youngest turns 2.
None of my kids ever had trouble adjusting, they all feel well loved, and we have plenty of time for them all.
Remember that newborns sleep a LOT for the first 3 months. You will have plenty of time to snuggle your 2 y/o.
I know it doesn't seem like it right now, but these things DO work themselves out.
Try to think of how EXCITING and FUN it will be for Josie to be a big sister!!! Instead of focusing on her not being a baby anymore. If you approach it that way, it can change your feelings, and can help influence her to feel involved and excited with you! instead of apprehensive or anxious.
There is a lot she can do to feel a part of it all. She can help you "pick" out clothes for the new baby. She can help by bringing you diapers. She can sing to the new baby.
And to help your mommy guilt, read stories to her when the newbie is asleep and rock her, just like you want to.
Don't worry it DOES work.