Flying Economy as a bigger girl

Hi all!

I have a flight booked next month to Singapore and I am really getting nervous. I am BIG - around 160kg (360 ish lb) I know that seats on planes aren’t exactly the comfiest even if you’re an average sized person.

Do any of you have any tips or suggestions or just plain old encouragement for making a 14 hour flight less of a potential nightmare? I’m already worried about who I might be sitting next to!

I have flown before, but it was business class so seat width wasn’t an issue.

Thanks in advance