Pregnant with my 4th!

I recently found out I'm pregnant again! My Baby girl is only 5 months! I have another 2 kids an 11 yr old and a 6th year old. I am happy but at the same time super nervous and sad because I wanted to enjoy my baby for a little longer. Any mommas out there have gone thru this?? please give me some advice and cheer me up cause I really need it 😁 thanks😘