What to wear to Sept wedding

[SweetPeaPods]

It's been a long time since I have been a wedding guest and last few weddings I was a bridesmaid so didn't have to worry about dress shopping.
Been invited to a friends wedding mid September. Not got a clue what to wear. I am the biggest I have ever been - currently around a 14. 5'2". Fee very self conscious and would love to wear something flattering especially on tummy area. I picked up a size 14 monsoon dress in local charity shop but it's black and wasn't sure if that was appropriate for daytime wedding that's not in the winter? Any tips for hiding recent weight gain or suggestions on places to look for the dress of my dreams in the budget of a stretched mum of 2. TIA

Forgot to add, gastro issues going on too so as well as bloat it's also uncomfortable. Really struggling with high waisted jeans at the minute for example.

Hello - yes, black is fine, and great for an autumn wedding. Good to add some colour in your accessories though - that's a pretty budget-friendly way to jazz things up a bit. If the Monsoon dress makes you feel good, that's what matters.

Thank you.