Help! To run everyday or not to run everyday?

Hi

I hope someone can help me as i'm sooooo frustrated and confused.

To cut a long story short, i started running in 2007 I got very good at it, won several races (including a marathon) and my weight dropped to 7 and half stone, dress size 6/8 from a size 12 (i'm 5ft 4in) - i looked like a long distance runner and felt great. I ran every single day and have done so up until Jan 2013.

I noticed about two years ago my weight started to increase but to be honest i was probably eating a bit more than i did when i first started running so i kind of expected this. However over the last 6 months my weight has gone up rapidly putting me at 9 stone, i feel puffy and bloated and really uncomfortable all the time - my thighs and tummy have particulary gained A LOT of inches.

Lots of people told me i was 'too use' to running and needed to shake up my exercise routine so at the beginning of the year i decided to stop running every day, introduce a rest day and do more cross training/circuits three times a week plus weights but after 4 months i feel like my weight is still increasing, none of my clothes fit and i'm so confused where to go now.

I know i didn't eat very much when i first started running and this has probably increased a bit but probably not enough for the amount of exercise i do. I probably eat around 1500 cals a day and very very rarely let myself have any treats or bread. I know there's this thing about stravation mode which i'm trying to get out of but how long does this normally take?

I feel like i should go back to running six times a week (3 days long distance, 3 days interval training), eat a little more, have one rest day and still do some circuit/weight training but nothing seems to be working at the moment.

Any suggestions or reasons why this might be happening would be gratefully received.

Thanks