Quit Smoking 2 months ago!

Hey all, I have been smoke free for 2 months now! I smoked for around 4-5 pack years since I was 15 and I am now 20 years old. Smoked roughly around a pack a day. I was doing great my first week after quitting (I quit because of a chest congestion/cold which got really bad) and during that week I was coughing up brownish mucus probably due to the quitting but also the infection. I suddenly started getting really anxious, twitchy and in a panic like state. Smoking was a way for us to deal with stressful situations, and while I occasionally woke up at night with a gasp for air and panic state, it never really bothered me during the day. Now since quitting I seem to have panic attacks all day long. SOB seems somewhat constant but can be followed by jolts (electric like feelings), palpatations, confusion and have now for the past week developed a persistent cough which may mostly be in my head. I'm not 100% sure what these symptoms are but I have had a chest x-ray, extensive bloodwork, physical by GP and Internist, urine test, bp which all came back normal. 1.5 years ago I had a workup on my heart because I had these symptoms beginning even while I smoked. (Echo, ECG, Stress) all came back normal. Just as a precaution I am going on a holter monitor to make sure there is nothing else and being checked for the possibility of thyroid issues. I am also considering having a CT scan to put my worries at rest. What I'm trying to say is that after quitting something that I used after fights with my girlfriend, after studying for a test, after being stressed at work, eating, after waking up, while driving, our bodies have had a major adjustment, our lung need to heal and believe it or not if you google Panic attacks, GAD or other things of that nature you will find that many symptoms are probably related to one of these conditions. They manifest themselves in very physical ways. We were self medicating with a drug (nicotine) and it was a huge part of our lives. Not having one can make someone feel depressed, angry, irritable so why couldn't it cause an increase in anxiety? I do think that everyone should have a work up to be 100% sure because after all we did abuse our bodies, but there is no reason to freak yourself out and get all worked up. You did a great thing by quitting so be proud of yourself! I hope that my symptoms eventually go away but ask yourselves if you had these problems before and you do need a full workup to rule out heart/pulmonary issues but really dont worry guys and congrats! I will post updates if anything comes up... I have been in hell the last few weeks but I am being optimistic. I've been very depressed, scared, isolated and thinking that I might die or have to live with this SOB for the rest of my life. It has had a huge impact on my life so regardless of whether its physical or mental I am still seeking therapy through my university. Perhaps you all should do the same if you can, sometimes talking and letting steam off to a stranger can help. Try it you have nothing to lose, if anything it will make your life better in different ways