Suggest Treatment For Low Heart Rate And Fatigue

I m a 40 year old male, prior athlete, and worked out extremely hard Have had a couple back surgeries over the last 2 years which have left me unable to do any physical activity. Have always had an extremely low heart rate, and was even hospitalized in cardiac units 2 years ago, with similar symptoms to what is happening now. At that time, heart rate was in the 30 s, but ruled to be totally healthy heart and slow heart rate was from activity level. Saw neurologist this week, and he checked my heart. Said it was in the low 40 s with a bunch of pauses/missed beats. He referred me to cardiologist, as i haven t done anything to warrant slow heart over last 12 months. I ve been suffering from extreme feelings of being light headed and dizzy (where I get to the verge of passing out especially upon standing), extreme fatigue, increasing headaches, and pain in chest that comes and goes. At times, my heart feels like it s beating out of my chest. Have a history of DVT s as well, in left leg. Should I seek treatment for this now, or wait until I can see a cardiologist in a couple weeks. Just wondering how serious the symptoms I m experiencing are. Would rather not go to ER unless this is an emergency. Have had these symptoms off and on for years, but over last couple months, have become severe. Thank you for you answer in advance.