8-10 crickets is far too little. The person who told you only crickets as a juvie was definitely wrong, yet again.

We had a decent discussion in the feeder section of this forum on staple diets that may help you out. Feed it a variety, earthworms, roaches, (if available) hornworms, (goliath worms) silk worms, morio worms, (commonly known as superworms), isopods, crickets, and the occasional rodent (pinky or fuzzy) just to name the more readily available feeders.

Underfeeding is probably what you are offering it now, feed it until it does not want to eat. (in a reasonable time, 15 minutes is normally advised)

Overfeeding does not typically occur when feeding insects, it can be overfed rodents, so use them only on occasion.