There are many kinds of Tapeworms and their eggs all look different. Search for "tapeworm segments" and click of "images" at the top of the screen.
Do any of these images look like what you are seeing? If tapeworms, none of the regular worm medicines work. Niclosamide is available on the internet from India. Only Praziquantel can be purchased here in the U.S.
I use the fish praziquantel for fungus. This is the one I buy from Amazon.com--Aqua Prazi Koi Care Pond Treatment Fluke parasite 25 grams. It is also available in larger sizes.
Re. your rash, there is a product called Tinactin antifungal with tolnaftate. It is a powder spray and it says it cures most jock itch. What it says on the label is "for effective relief of itching, chafing and burning". It's an idea--might help.
The castor oil is a great first step, but I don't know about taking it daily. Take a good dose once to clear your colon--take again if you need to. Take on an empty stomach. Early morning works for me so I don't have to be up all night. I take with grapefruit juice, stir briskly and gulp down. It can work in only a few hours.
Keep us posted if you don't recognize your parasite in the images.