need help to go blonde.

I need some advice on how to get my blonde hair.

Here's my story:
I have naturally curly fine hair.

I have always done a sandy blonde or light brown all over color on my hair. Around july of last year I decided to highlight my hair with a bleaching kit. I did this process 3 times about 6-7 weeks apart. The first time it went great. The second time it went well but my hair was a little dry. The third time my hair got severely over processed and my hair broke off in some spots about 2 inches from the scalp.

Around thanksgiving I decided to do an all over dark brown (which turned my hair almost black) to try to make my hair look healthier. It sort of worked. Since then I have been doing deep conditioning treatments twice a week using cholesterol, and using a protien leave in conditioner. As well as taking hair vitamins.

The hair color has now faded to a very unfortunate and mousy shade of redish brown. And I really want to get it blonde again but I don't know the best way to do this.

Will a non bleach bottle color do the trick since the old color is so faded or am I going to have to strip the color and start all over?

Any advice is helpful and welcome.