Heavy Bleeding Lasting Over a Month

I am 21 and have never really had regular periods. For the most part they lasted at least 2 weeks but they were never heavy like they have been this year. I never know when to expect my period to come but usually I have light bleeding at first, the past few periods have been almost a pint of blood at once along with gooey blackness (lining I think).

I am too afraid to go to the gyno, could this be something really bad? I have never seen a gyno and have severe anxiety.