How concerned should I be with the following symptoms I am having?

I don't think anyone can reliably diagnose what you describe over the internet without an exam and testing, which is what you are going to do. The time must seem like forever, I know. But listen, there are a number of causes for bleeding between periods, whether it is slow, like yours is or faster and not all of them are serious, most of the time they are not, and a cyst can cause you some of these symptoms. Remember that a condition does not have to exhibit all of it's symptoms and many are interchangeable between conditions. So the gynecologist needs to sort these out.

The light brown is older blood, and here is some information about the types of discharges, while not inclusive, it does help a little. Whether all of the symptoms lead toward one single cause or you have several things going at once, we will have to trust that the doctor will be able to find the reasons. Then you can make decisions about your health and how to help it. Please try not to worry too much, you have done the logical step in seeing the doctor.

Try to make a list of questions you would like answered, all medications you are taking, your symptoms and approximately when the started and your history, as you have done here, if they don't have it. I wish you the best of luck.