Seems to me you smoked methamphetamine
or "ice" the street name.There nothing much to worry about it is a very powerful stimulant and when you come off the drug it very normal to have withdrawl symptoms such as :
or feeling low
2.Lack of appetite
Now the above mentioned symptoms like the ones you are having totally depends on the purity of the meth you smoked the higher the purity the worse these symptoms are going to get. You can try having yoghurt and have green tea this will help you in getting back your normal energy levels.
But smokers of meth experience such drastic symptoms only after a year of using or so, for a first time smoker this is pretty rare.Wait and watch for a week or so and even then you do not feel better plz consult a physician and get the appropriate tests done to avoid any further damage to your health.And plz refrain from using such hard drugs.
Thank you and take care