I just posted this yesterday in a similar thread so I am just copying it here
Assist feeding should be done as a last resort
If you have not done so here is what you need to do
Set your snake up in a 6 quarts tub (max) with aspen as bedding, use a plastic flower pot saucer as an hide (6 inches wide)
Provide a hot spot of 88 degrees (max), leave it alone for a week (no handling) and offer a live mousse hopper in the enclosure. Prey should be as big as the girth size of your snake.
Stick with mice for now as they are more enticing.