I have a 3 year old and a 13 month old, so it isn't quite the same but similar. I have been struggling with the exact same thing since my daughter was born. I find it interesting that you said, "I have a 3-year-old who I absolutely ADORE, and a 4-month-old who I'm growing more and more attached to each day." That was my main problem. I was and am so attached to my 3 year old son that I often feel incredibly guilty that I don't feel the exact same attachment to my daughter. I love her dearly, but it is totally different. I think this is normal, but a hard thing to get used to. Then I get to feeling guilty that I don't get my son out to do more now that we have the baby to take care of. I guess I am not helping much, but as you said sometimes it helps just to know others feel the same way. I got to the point of feeling so stressed out that I went to the doctor and was diagnosed with post-natal depression. I am not saying you need that kind of help, but it is something to consider. I can honestly say it is still hard, but I have felt MUCH better since I got some help. Depression isn't just crying... it is all those things you mentioned - feeling lonely, isolated, overwhelmed. If you want to message me further, feel free. I don't live close to you, but would be happy to email or talk. Good luck, and God Bless.