It is common to have a drop in supply in the evenings. But drinking water, taking rest whenever possible and eating a balanced diet should help. If you think your baby doesn't get enough, try breast compression, if you need more info on that, let me know. This helps baby to get all milk in your breast, especially the fat rich hind milk which keeps him full for a longer time.
However, I personally don't think your supply is responsible for his wakings. It is still common in babies to wake up so often, however difficult for us, sleep deprived moms. There are those lucky ones whose babies sleep through since very early and those whose babies don't, even till 1.5 year old.
The reasons for your baby awakenings may be: hunger, but also need to be with you, be hugged, not being able to get back to sleep and so on. I had exactly the same problem with my dd. She was a master of frequent wakings. I tried many things and honestly she was just such type of a light sleeper. From my personal experience, dream feed wasn't helpful as it disturbed her sleep and she developed a pattern of waking at around the time of dream feed. I also noticed that my attempts to wake her up often to feed in her first days/weeks created somehow this problems with sleeping, almost as if I taught her to be awaken often and not let her sleep as long as she would like, if you understand what I mean.
