vibrators and loss of clitoral stimulation

I started using a vibrator for the first time about a month ago. The first time I used it, I was able to orgasm back to back to back. A few times later, I got this tingling sensation in my clit that would not go away. I then placed ice on the tip and it went away. That feeling has not returned and I then continued using my vibrator again. Now I notice that my clit feels a little numb and desensitized. I am trying to find out what could be the cause of this and what I need to do to get my regular sensation back. I used to be able to have orgasm with just hand stimulation, but lately that's not working. I have also read some posts that talk about this in terms of nerve damage. I am wonder if after just a month of use I could have nerve damage. I do not have any pain in my clit and it isn't swollen just less sensitive. Also, are there any treatments available if I have caused some damage.  

Thanks in advance for your guidance.