You can apply on your own but I would not recommend it. You have to look at it this way, you're attorney failed his first go around, what are the chances you will succeed without the training and knowledge he has? It most likely take you much much longer to make the proper corrections and more likely to get rejected again if you do not use an attorney.
I would recommend going to a new attorney and having them pick up where he left off. Hopefully the cause for rejection was clear.
When I stand before God at the end of my life, I would hope that I would not have a single bit of talent left, and could say, "I used everything you gave me."