Ryanair seat size concern!?

I am flying to Germany in 2 weeks time and have never flown Ryanair before - I am not too worried about baggage etc I think I'll be OK however I am slightly worried about their seat size. Having recently flown with KLM and finding their seats snug but comfy for a 14 hour flight I am worried about Ryanair. I am a UK size 20/22 and am 5ft2 - I carry most of my weight on my hips (unfortunately) and I am slightly worried about getting the seatbelt around me! Does anyone have any experience with this? Please don't tell me to "lose weight" and please don't be mean - I don't want to hear things like "if you're worried, lose weight" etc, I am simply asking for advice of people who have experience with this type of problem! :)