Perhaps you have hangups about sex? Maybe a strict/religious upbringing?
I only mention it because dildos are in many cases a vital part of sex in terms of foreplay and preparing for intercourse. A virgin will never be able to take a large penis without some sort of dilation/stretching routine.
You will either need to use your fingers (or someone else's :wink or a small dildo and increase the size. eg one finger, two fingers, etc.
Maybe if you have never stretched yourself or stretched with regularity then you are small down there. But with a regular routine of stretching/penetration incorporated into your masturbation you will become more accommodating.
Of course this doesn't matter if you don't intend to find a large penis'd guy or if you would turn such a guy down. Although if you find even 'average' sex slightly uncomfortable then flexing your love muscle is recommended.
The only issues I have had were with girls who masturbated just by rubbing their clits. This made them extremely tight.
well i'm not a virgin, and yes, i was brought up religiously, but don't believe in religion myself. so no, that has not had an effect on me, personally.
thanks for the input.