Maybe make sure youre not as tired when you start your meditation. Or add some movement to keep you awake like stretching!
Try short meditations in the beginning. Reduce the time such that you dont have enough time to fall asleep. Once you are comfortable with that time-period, gradually increase it.
Another you can try is energy breathings or taking a power nap.
Meditation is not something that is to be forcefully done. You have to let your mind and body free and dont force anything.