Hi, Anon, and welcome to EmpowHer. Thanks so much for your question.
I'm sorry you're dealing with this much pain. That's not a normal way to live, and it's a signal that something's going on. Let's see what we can figure out.
First, on the abdominal pains. How long has this been going on? You say that you are in the middle of your cycle, and I'm wondering if you could be having ovulation pains -- in other words, pain when your ovaries are releasing their eggs. Does it just happen in the middle of your cycle, or is it pretty constant and happens every day? Have you ever had or been examined for ovarian cysts or endometriosis?
Here is a page that talks about ovulation pain; do the symptoms they describe sound like yours?
And on the pain during sex, is this pain related to the other pain? It sounds like you are describing something different. It sounds to me that you are describing sensations in your vagina. Is it the walls of your vagina that feel incredibly sore? Where exactly is the burning sensation? Is it inside the vagina? Up at the top, where his penis might be coming in contact with your cervix, or more on the sides, or more at the entrance?
Some vaginal infections can cause pain, itching and a discharge. They can even have symptoms that go unnoticed until sex, and then sex can inflame the infection and cause all these symptoms. Here's a page that talks about this:
Here's a very thorough page on vaginal infections (and on treatment) from the Merck Manual:
And here's one other page on pain during intercourse that covers a lot of possibilities:
None of this is uncommon, and you shouldn't be shy to ask a doctor about it if need be. Do you have an ob/gyn that you like?
Does this help? Do these overviews give you any idea of what you think might be causing this pain?