Hey Mariah,
For background take a look at my story - the link is in my signature.
I have similar symptoms. I have difficulty breathing and an inability to breathe through my mouth. And I do feel like there is a small lump in my throat. The lump clears if I inhale steam, it feels like it dissolves with the heat. Although it quickly comes back as soon as I stress even a little. (Have you treid inhaling steam? Does it temporarily lessen that lumpy feeling. Works better if you use those carvol tablets. )
I have difficulty swallowing too. So there are muscular issues too. To make things worse I have nasal polyps and spasmy feeling in the sinuses that make it harder for me to breathe through my nose. And that coupled with not being able to breathe through my mouth has be short of breath for the whole time. It gets harder to breathe if I lie down. I have a chest spasm too. So breathing through the mouth makes that worse. So I never breathe through my mouth.
I think there might be issues of asthma, autoimmunity and muscular weakness involved. I've been to the pulmonologist and the cardiologist. But nothing came up. I've been to the ENT too but not have had a throat inspection or a scan of my sinuses. I'll be doing that in the next week. Will keep you updated if anyhting comes up.
Right now, I'm having a terrible time eating. I am eating so much less now than earlier. For the record Clonazepam eases my swallowing and breathing troubles. So mine is a lot muscle weakness related but there is undeniably an autoimmune asthmatic component here.
Regards,
Arun, India.