Shopping around for a better rate will involve your credit report being pulled over and over. This will lower your credit scores, thus increasing your rate. Every time you apply for credit an inquiry appears on your credit report. Ideally, you should limit yourself to one inquiry every 6 months (4 inquiries every 2 years).
By taking out a small loan you added a new inquiry on your credit which likely lowered your scores. You also opened a new account which may also lower your score. Finally, a new account also impacts your Debt to income ratio.
Our advise would be to contact your loan officer, tell them about all of your recent credit transactions and stop applying for credit.
If your interested in learning more about inquiries, here is more info: http://www.creditfirm.net/blogs/what-you-need-to-know-about-credit-inquiries.html