When I was younger and healthier, they used to give me a boost the day I got it and a few days afterwards. I got one around a year ago and it was about a two minute buzz and taste in my mouth, period. good luck
Usually they should give you some kind of a boost. I personally would advice to get your vitamin levels checked, also your vitamin D levels, before getting the shots.
Marcia
P.S. Sorry to hear you are feeling so tired, I was like that already for 6 months before I started treatment. Was mostly in bed, already then. I hope you will find something to help you.