Not sure APS, lungs or heart?!?!

I'm new to this so here it goes... I have a major request that I would like some opinions on. I have been feeling lightheaded and heavy chested (feels like something is in my lungs, like a toxic gas or something) for the past 4-5 weeks, and now feel a sense of hot flashes around my neck area (usually after eating, but even lying in bed, now just randomly at times). Sometimes, it feels my blood pressure goes up, and at other times feels down. Even at night, I sometimes feel lightheaded, so I need to get up and drink water. It was on and off on some days, but recently has been getting worse, even on a daily basis (most recently hourly) . I already went to the ER once a couple weeks ago, then again this past Thursday (and almost 2 other times) where they took a CAT scan to check my brain and lungs. I have also been doing all sorts of blood work to check for internal bleeding, anemia, my iron count and even my thyroid. Still waiting on my hypothalamus test, which my friend suggested since I get those funny hot flashes around my neck.

By the way, I also had a PE (clot in my lungs) in November, where I had similar symptoms, but was taken care of with blood thinners. I also was recently diagnosed with APS Antiphospholipid syndrome (which causes clots), but when I went to the ER on June 27, they found none (via contrast CAT scan). My doctor and hematologist both said that I need to be on Xarelto for the rest of my life, but that it should not cause all of these symptoms.

So, the good thing is that everything is normal (at least from a medical perspective), but the bad thing is I don't know why I'm feeling this way, and it feels super terrible. I think I already had 8-9 blood work done within the past few weeks, and it makes me feel down. During the past weeks, I felt 50/50 on whether to go to the summer school each day, thinking whether I can make it through the short day. Last week, I went to see an ENT (everything was clear), and then a neurologist this week. My primary care giver has tried to help, but he (as well as I), are running out of options. Others have suggested a cardiologist which I will see on August 8. Recently as of Thursday, my chest has gotten sore while lying down. That's the reason why I went to the ER on Thursday, because I got up after only a couple hours with my heart racing and my body flushed. I am getting so desperate and distraught. Any thoughts, suggestions, or words of advice from anyone will help...Scott