Congrats on your success!
I'd suggest that you set yourself up a good schedule so you have time to dedicate to your school work and your shop.
I'd also be sure to set up a business plan and a budget for your shop.
You may also want to take a good look at your pricing strategy.
Pricing is generally based on
1) cost of materials
2) cost of your time
3) other expenses (paypal fees, etsy fees, etc)
4) profit you want for an item.
This total gives you your 'base' rate or wholesale price - the price you would sell at if you were selling a large quantity of the same item.
Your retail (Etsy) price is generally 2x your wholesale price.
So when you look at your Peter Pan collars
http://www.etsy.com/listing/121332648/ivory-pearl-peter-pan-collar-necklaceare you really pricing so that you are making a profit at $20 each once you've paid for your time and materials?