3 months away and still stressed :(

I did as much as I could in 1 month of planning. I unlike most brides dont have a year to plan. Got engaged in May and married in September. My fiance and I have paid off the venue, put down deposits on the dj, photographer, officiant and decorater. And we sent out invitations last week. Why am I still stressed? Not sure what to do as far as catering because I want buffet style/self serve but not tacky. I found the perfect wedding cake. My wedding is at a beach so minimal decorations are needed. What else could I possibly be missing? What's really necessary at a beach wedding? I feel like I'm over thinking this process.