Ejection fraction. As my age is just 25!

I am 25.One day while I was smoking my heart rate raised to 160 along with my bp. Panicking I went to hospital and on some medicine ingested through veins my heart rate was normal in 2 hours. They put me in hospital for 2 days to see if the episode occurs again and did various test which were normal. They discharged with promolex . I referred another doctor and he said I have low ejection fractions ie 50. He did BNP test even that was normal.He still gave me valsartan 80 mg and lanoxin. Everything was fine for a week and then at night I started getting tingling sensation in various body parts like bp was raising. My dilemma is before 4 months I had my body checked along with bp and everything was fine. So what is happening and what should I do in this situation. For now I have completely changed my life style like no smoking and no fats. Please help me as am getting depressed by all this as my age is just 25