Hello, and I hope I can help you today.
When you are aroused before having sex, the vagina normally becomes looser, the skin swells and becomes thicker, and the vagina lengthens. That is your body's design to protect your vagina from trauma from intercourse and also prepares your body in the best way for sperm to swim inside you for your natural
fertility.
If you are not aroused when you initiate sex, your vagina is narrower, dry and not as resilient, so it is not unusual to have chafing or pain, especially after the sex has finishes and you are not distracted. The vagina is a delicate part of your body, and sex especially if you are not lubricated well can scrape your vagina inside and out and also scrape your
urethra (the opening where your urine comes out) which is why it burns when you urinate after sex. Also, if you are using a condom, the rim of the condom can irritate you and as you mentioned, so can pubic hair at the base of the penis. You literally can get bruised also from having intercourse especially if it is rough.
You had the right instinct to use coconut oil to soothe the area, but the time when you need the additonal lubrication is at penetration and during sex, not after.
So I suggest you and your partner use a lubricant before initiating sex if you are not fully aroused. If you are using a condom purchase a water-based lubricant, but you can even use the coconut oil if you are not using a condom. It may also help if your partner trims the hair at the base of his penis to reduce the chafing.
The main thing that concerns me about your story is the sores you get after sex. I have concerns that this may be
herpes which is a type of sexually transmitted infection. An
OBGYN doctor can test you for this if you can try to see them when you have the bumps so they may be properly examined and a culture can be done to check for infection. I would suggest both you and your partner see a doctor and get
STD testing especially if you are having unprotected sex. Also if your burning with urination persists, that can be a sign of a urine infection which needs also to be evaluated and treated by a physician.
I hope I was able to answer your question and that my advice was helpful.
Best wishes, Dr. Brown