Vomit Tapeworm?!

If a human has a really bad tapeworm infection is it possible to vomit parts of a tapeworm after eating?  I have had a parasitic infection that I've been trying to get diagnosed for about three months now, but have only done one stool test that came up negative and I am waiting on the results of another one.  I've developed symptoms about 9 months ago, but I have had severe constipation for about 4-5 years where I would go about once a week, but it got so bad I went 16 days without about 3 months ago.  I've developed really bad bloating and noises in my stomach can actually feel stuff moving around have been nausious and vomiting on occassion and have been so tired I can hardly get out of bed.  I've had a lot of vaginal infections with group b strep that i never had before.  I've recently started getting headaches and pretty dizzy when I get up from laying down.  I've been seeing small worms in my stool for awhile now and I initially thought it was pinworm, but have noticed that the worms are longer than what would be a pinworm.  Tonight I vomited and with my food I had what looked like a worm I've been seeing in my stool, but a lot longer it was about a half inch wide and 1/4th inch thick and about 3-4 inches long, but it was not white it was kind of a dark brown color, but the inside was a whitish color.  I've been seeing parts like this in my stool, but little pieces.  They kind of look like pieces of olives, but they aren't.  Then I have also been seeing pieces that are white that definitely look like tapeworm pieces.  Can anyone give me any advice on this?  I am waiting for a diagnosis and I just don't know what kind of worm this is.  I'm seeing small ones long ones clear ones dark ones and white ones and yellowish looking ones!  I am also taking stuff from a health store that has good parasite killing ingredients, but I took it for a month and got a lot better and stopped for a month and now it's just as bad.  So I know I am killing some, but not all of it.