Oriental Poppy allegro advice please

I purchased a oriental poppy in May and put it in a container with general compost, it grew rapidly and I was very pleased as I'm quite new to gardening. However, it's leafs have started to go yellow and wilt. I don't know if I'm over watering or under watering. It appears to be shrinking and when it produced 2 two flowers they were weak with white dashed through the red, and they looked limpist. I've notice tiny tiny flies crawling on the soil, could they be the problem? I've tried looking it up on the internet but haven't had much success. I welcome any advice you may have.

 

I think oriental poppies go dormant after blooming, so may be your plant is just completing its yearly cycle at the moment. But I only had one OP in my life and it´s been left behind in my old garden so I don´t have much experience there.

As for the crwaling flies, in doubt spray some pyretrum on the ground and plant two or three times over a couple of months.

 

Thank you Ivory. Unfortunately, I think I might have killed it, I took the plant out of it's pot to check the roots for any disease, and they looked fine. The problem occured when I tried to get it back in the pot, the leafs ended up in my hand, and the soil and roots went back in the pot. Is that the end of my oriental poppy?

 

Keep it around in some shady corner when the pot will never go totally dry, and next string you will know.