No, we can't maintain oxygen level and decrease pulse rate with home remedies.
Understand the situation and accept it and get evaluated for covid 19.
Next Steps
COVID 19 RTPCR
Consult Doctor of your choice.
Deep breathing exercise and avoiding anxiety/panic will help a little.
Steam inhalation
Gargle with lukewarm water
Health Tips
Look for breathlessness/severe cough/chest pain/ increase in pulse rate more than 120/min