Fingernails Turning Blue/Purple

I noticed a little over a week ago that my fingernails were bluer than usual. My mom tells me they don't look blue, but I don't know why I would have noticed it if they weren't. I've been having some shortness of breath, feeling like I'm not getting enough air, and it feels like there's a lump in my throat right around my sternum.

I've had severe depression-like symptoms for a year and three months now, and lab work has shown poor adrenal function. I thought it might be para-neoplastic Cushing's, which is caused by small cell lung cancer. I haven't been coughing up or vomiting blood though, so I'm not sure what to make of it all.