Jhana Meditation

Since returning from the Vipassana retreat, I have been practicing daily and been able to maintain access concentration (following breath)diligently. In the past week I have been taking my meditation a step deeper. Observing the breathe first, I have now introduced Piti (the 3rd factor in the first Jhana), which is the observation of pleasurable physical sensation. It was recommended to use smiling, as it generates feel good endorphines. The concept behind observing a pleasurable physical sensation during meditation is that it creates a positive feedback loop to the quiet and still mind, the pleasant sensation grows in intensity until it explodes into ecstacy. Physical pleasure followed by emotional pleasure. The most difficult part is not to be attached to the pleasurable feeling. Just observing. It has been difficult maintaining Piti for more than a few minutes, as the mind naturally wants to attempt to increase the pleasure which interupts the process. I have though, experienced short moments of an altered state of consciousness, it is an experience beyond description. Sleep again, is being disturbed, that is of course only counting those few times where I have been able to fall asleep. I am so tired during the day. When night comes, I want to play. I am so hungry at night time as well. I have had to force myself in the past few nights to not eat anything, because it is creating discomfort physically.