what are the problems of swollen feet in type 1 diabetes?

I've had type 1 diabetes for about 4 month and am on insulin injections twice daily. The last couple of days my feet have been sore and today when i got up my feet and ankles were swollen as well as sore. Lastly, my toenails have become very thick, brittle and of a yellow colour. Can anyone give me any advice please.
i have been diagnosed with type 1 diabiites for a few months now. i have noticed over the last couple of weeks my toes nails habr changed colour and texture. they are becoming yellow and brittle. now, over the last few days my feet semed to have swelled and my legs are doing the same.