I Started Getting Congested Last Saturday , Got Worse With

I started getting congested last Saturday , got worse with body weakness and fatigue finally Thursday went to the dr and was given antibiotics for a sinus infection. I've been taking them since Thursday night. Ended up getting a very tight neck Friday night and now Saturday my legs, ankles to my knees are very sore and kind of tingly. What is going on? Sidenote I have also had a high heart rate for awhile. Went to PCP he did an ekg and said it was normal and probably anxiety. I'm going to follow up with a cardiologist in a couple weeks.