Opinions/advice on adding another baby

Tiff • My twins are 14months and we have a 5 year old, all girls! Contemplating the possibility of trying for a boy :/
I have been very hesitant on posting on here so I'm praying for the best and hope you guys are respectful of my feelings and don't give negative feed back.
My husband and I are in our mid 20's, together for 7yrs, married for 5yrs, own a home, 3 vehicles, we are pretty well set and stable. 
We have 3 daughters, 5yr old whom of which is our rainbow baby, and twin 14 month olds.
Obviously he wants to try for a son, my feelings are extremely mixed as I am a stay at home mommy and get overwhelmed at times because my husband spends a majority of his time working. 
My 5yr old starts school this year and I'm getting very depressed because she is my little helper with the twins and I'm very attached to her. For some reason I think my feelings of her not being here when she starts school is causing me to have baby fever because I haven't been making him use protection. 
I'm scared, confused, just overall extremely mixed, especially because I have strong feeling we will have another girl.
And input would be greatly appreciated!! Thank you so much in advance!