I am 20 years old, I have been fingered and had oral sex numerous times, but for some reason I simply cannot use a tampon. I have tried several times but I get very nervous and tense and each time I try, I get more discouraged. What I don't understand is why I have no problem being fingered or receiving oral sex, but when it comes to tampons I just can't do it. How do I get over this mental block?