All of a sudden very sad about having baby #2

I am 37 weeks pregnant. This whole pregnancy I have been super excited to share this experience with my 5 year old son. Now, he is from a previous relationship and I technically have him 5 days out of the week.. but with family wanting to spend time with him I get about 3 full days. Normally that’s fine! I would rather him go have fun with his dads side of the family or my parents...

but all of a sudden I am realizing when this baby gets here.. I’ll have no more alone time with him. Everything will be both of them and I’m really sad about it.. like constantly crying and apologizing to my son for this...