Mirena and cold sore

Having read all the other peoples comments, am feeling a little less like I am going mad! I am 33 and have no children and had the Mirena coil fitted 18 months ago to combat VERY heavy periods and a dangerously low iron level (i suffer from PCOS). All seemed to be going well for the first 6 months or so- still bleeding but less heavily and a little bit of weight gain, but nothing too scary. Then 9 months in I got what seemed to be a very bad case of herpes the doctor didn't do a blood test, but did give me medication and pain killers.....I have been with my partner for 4 years, we are both faithful and I have never even had a cold sore before!
In the past 9 months my period have been getting more frequent again (one every couple of weeks for about 5 days) but not as heavy as before AND I am getting a very swollen every month with dry itchy areas and sometimes a blister! Does anyone know if it can cause a dormant herpes infection to become active? I am also putting on weight more and the mood swings are getting more pronounced....lots of uncontrollable for no reason and my sex drive is either very high or not there.
I think I will get it removed, but I am scared of the effect this will have on my periods........can anyone help!