Very long and heavy periods

Please help,I am in tears as i am writing.
I am 38,always had normal periods,then last january for the first time i missed a period.My period fynally came on the 9th of february,but apart from a few days here and there it has not stopped,it has been very heavy at times then light and then heavy again and most of the times with clots.My blood test showed my hormones to be slithly low.What is happening.
Please help if you know what it could be,i am sick with worry.
Thank you