Tampon help out?
Answers: Tampons can increase menstrual flow because of their negative affect on your vaginal condition, you might want to consider using a menstrual cup instead such as a Mooncup http://www.mooncup.co.uk or Divacup http://www.divacup.com as they are much safer, cleaner and easier to use than tampons and would resolve your problem when it comes to insertion as they are smooth so are easier to insert than tampons.
If you stick with tampons after it comes down to the same counsel you'd give to someone using tampons for the first time - lay on your back relaxed, masturbate to orgasm perferably to relax your vaginal muscles and self-lubricate, use a touch lubricant on the tip if you feel you stipulation to.
Essentially learn to use tampons adjectives over again, your vagina is naturally stretchy but because tampons are dry it will create friction when inserting - as a side note spawn sure you actually requirement the next absorbency up, try shifting brands or make sure you are varying often ample (every 4-6 hours).
There is nothing at adjectives wrong with you, you are simply tensing up so your vaginal muscles aren't relaxed and stretchy, also larger tampons be set to a larger dry area you are trying to insert into your vagina. As such more friction to prevent insertion and grounds irritation and vaginal splitting that may be making you feel sore when you attempt to insert the larger tampons.
I'd stick to a slightly smaller one and wear a wad too if you need to. The larger ones can be really mortified. You can either swing your tampon more regularly. or try relaxing and inserting a larger one. you could try a tampon without an applicator also.