Hello!
The first thing you should check is the equipment you are using to check the heart rate, you need to use a well calibrated machine.
Get yourself examined for all vitals by a physician and calculate your BMI.
Also get an ECG done and if you do not have any issues with your heart such as arrythmias and palpitations you very well can continue your regular cardio.
Take care!
You have a compensatory tachcardia.
The problem is with such a high rate (a) the heart does not completely fill with blood and (b) there is an increased probability of developing ventricular fibrillation. Ventricular fibrillation results in death unless a defibrillator is immediately available.
You feel out of breath because although the heart rate has increased the volume of blood has decreased because the heart is not filling between beats.
First of all, stop immediately performing thirty-minute routines. You are endangering yourself. The degree of danger is not high, but enough to make one wary. Confine yourself to fifteen-minute routines.
Secondly you need a complete cardiac evaluation. And EKG is not enough. You require a full stress test.
I suggest you see your MD for a checkup