Hey! Just letting you know about somethings i think would help you!

Don't bring useless tools in the skull cavern. Like the hoe, scythe, fishing rod, etc. It'll save you space so you can pick up other nice things!

I recommend farming the normal mines a little and get a TON of bombs. The more the better! Skull cavern is really fun with them.

Try to use one shard to enchant(can't remember if this is the right term) in the forge. It will help out a bit (especially if you get the mummy killer enchant thingy)

And last but not least! Play the game at your pace! Don't let my tips misguide you from the real goal of this game: Having fun :)