Hi,
By breaking hymen the vaginal opening will not become bigger but it is necessary to break it for intercourse. Normally those who are involved in sports and other similar activities will have their hymen broken before the intercouse. Otherwise the hymen will break in the first intercourse. Some women will have a very strong hymen which will be difficult to break through intercourse. Such cases are very rare it can be broken by medical practitioners.

Vaginal opening will become bigger through intercourse and it will get much bigger by delivering babies. If your husband is having problem with the foreskin that can be corrected with a small surgery.

If you are not having a successful intercourse then you have to make sure that if it is due to your hymen or not. As I told you earlier the hymen should be broken to have a successful intercourse. Is he able to enter you? Is he having some pain or something on his penis while entering due to the foreskin?
Are you getting enough lubrication for him to enter. What about his erection?
If he is unable to enter you even with a very good erection then you have to check the status of your hymen. Consult a good doctor who will be able to rectify it. You should make sure that there is enough lubrication in your vagina. Then involve in foreplays to get him and yourself ready for the intercourse.