Have Quit Smoking. Low Pulse, Feeling Tired, Throbbing Region Above Knee. Is This A Known Phenomenon?

Hi, I am 26+ years old, I have recently quit smoking having smoked for the last 10 years. During the last 10 years I have been very active at playing competitive football (soccer) and on occasions where I ve visited my GP for the odd health/injury issues I would have my BP checked (though i can t recall the reading) and my pulse is quite low compared to the average person (apparently this is normal for athletes). I am now less active and haven t played football in the last 3 months. My question today is, since quitting smoking, I have been feeling tired, but quite alarmed at the fact that there s a region about 6 to 7 INCHES above my left knee (inner thigh), it s visibly throbbing/Pulsating and the skin surface itches a every now and then. The pulsation is pretty much constant at varying rhythm. Also i get shooting pains at random spots in my body, e.g., wrist , ankle, inner left arm, e.t.c. please is this a known phenomenon and if so, is it a negative one? thanks a lot in advance