Why does my vagina feel painful during the second round? this happens every time when my partner has come inside me, but not happening with a condom. this has been like this for my whole life. i'm 30 now?

You may try using a liberal amount of a water based lubricant like K-Y jelly. Condom may have a lubricant on the outside. If you do not wish to get pregnant, use contraception all the time, every time. For healthy diet: http://www.choosemyplate.gov/., exercise 30 minutes/day, drink enough water daily so your urine is mostly colorless, have safe sex, no tobacco alcohol weed or street drugs.