Do you think this could be heart failure?

[Cubedg]

Hi, I'm 19 and have been having some really weird symptoms that have been persisting and have been really scaring me into thinking I might have CHF. I have had like jolting chest pain on and off that gets worse with stress but comes more dull just sitting/lying around. I don't tend to get any shortness of breath much that I can for sure know because sometimes I feel like its just my thoughts causing me to think about it more than normal. Recently I got like a really annoying, hacking cough with white bubbly phlegm. I also have been getting some joint pain in like my fingers, ankles, wrists, etc. and also some occasional leg pain too. I don't really know what swelling would feel like, so I'm not sure there. I've been to both my fanily doctor and a cardiologist and had 2 chest X-rays, 2 resting EKG, a set of blood work, and a stress test come back fine, but I'm still worried. From people that have had CHF, what should I look for/ what do you experience, and should I get a second opinion/more testing?