Penny. You sound like an incredibly strong woman to be dealing with everything that you have been going though, all that while doing the hardest job in the world - being someone's mummy!
All I can suggest is that you visit in here while TTC. You will find a wealth of information and support from girls going through similar experiences. And we all need to vent now and then.
Another option you could try is to give TTC a break for awhile and focus on yourself. You need to keep yourself healthy and strong, for yourself, your family and a future pregnancy. Everyone in here would miss you, but taking a break from BB and the all-consuming task of TTC might be what you need. Do you have something else to focus on for yourself - a hobby or something? And eat healthy. You might find that when you are healthy and strong (emotionally as well as physically), another LO might decide to join you.
Take care.