I had this in my 20's. Ugh. I also produced too much estrogen and had a slow thyroid at the time. It was a big pain. I had all sorts of symptoms including periods only every 3 to 4 months. Have they suggested an MRI? One thing that causes this is a tiny, harmless, benign tumor in the pituitary gland. I was checked for this. (I didn't have it). I was headed to an endocrinologist and my symptoms got better before my appointment. I had the issue for about a year and a half and I'm not sure why, but I just went back to normal on my own while waiting for the specialist appointment. Talk to your Ob/gyn about why you are having this issue.
And yes, this probably causes you to be irregular and results in difficulty getting pregnant. Again, mine resolved and I have two kiddos. Hang in there.