Matalan moment AGAIN - I am annoyed

about 7 years ago I went to matalan one christmas and virtually nothing fitted - size 20's were tight and 22's just hung on me and made me look like a sack of spuds ! After a full week of annual leave and eating out most nights and indulgencies for Koz's birthday and chocolate etc etc - I gained 4lb's in weight - in one week - on top of the 1stone 4lb's I had already regained - and now size 18's are all I can get in to - and SOME matalan 20's were tight on me (the fitted ones) - I nearly cried. So as OF NOW I am back on Slimming world - plenty of fruit and veggies and small amounts of meat and carbs - it has to be done, I hate hate hate feeling like I do again.