Welcome to HCM,
This is not true, if some body told you it is myth. In fact sugar is good source of energy for immediate use.
Only in diabetes
long standing they may have ED. That too have many reasons.
The problem you are facing is premature ejaculation
hence please consult good Urologist
Take care of your diet and exercise and if you are stressed take up some yoga and meditation
Now there are few drugs from very short acting SSRI like Dapoxitine which you can get on prescription.
Please do not compare to your friends as in reality they exaggerate the things.
Please take care