Both of my boys are mamas boys and have been since birth. My husband works evenings and I stay at home with them. Whenever I leave my now 22 month old with a babysitter , it turns into quite an ordeal. Hysterical crying, death grip, and lots of guilt. I know that this time frame age wise is very typical of this type of response- but it doesn't make it any easier.
Some things to make the time away easier:
1) It is like ripping off a bandaid but once I drop them off I leave pretty immediately. The longer I stay the longer he yells.
2) Familiar Toys- My little one loves Thomas the train so much so that he sleeps with them at night. So I make sure he has his favorite toys available.
3) Familiar Person- If I can I try to make sure he is with the same person as much as possible. Too many different people makes it harder for them to feel comfortable.
In my experience I have found that the crying and hysterics are only temporary by the time I come back and peek in he is playing and fine. Now when I announce my presence the hysterics start again but to get him. If I didn't know any better, I would swear he was upset the entire time. As with all things with time and diligence your little one will start going easier on you and actually have fun when left with your babysitter.