Possesion w/ Intent to distribute (Marijuana)

5 months ago my girlfreind & I were picking up her cousin Jack in my car from his home to go to the mall and I had three ounces or weed in my jacket. Coincidently narcotics police were watching Jack's home & were preparing to execute a search warrant when we picked him up. I was pulled over a few blocks away and the narcs found the weed I had on me. I was cuffed & placed in the back of the narc car with Jack and they brought us back to his house as they searched. As this was going on, a narc brought me aside & asked me if I had any more weed at my home. I told him yes I had about a half ounce more at my house. He then told me it would look good in court for me if I brought the police to my home to confiscate the half oz and I agreed to bring them there. Along with the weed, they found a scale, baggies & $1,500 that I forgot about all in the same backpack together. However, the apartment I was living in at the time was not officially rented out to me- my girlfreind was considered the tenant and was not present at the time I gave the cop permission to enter the apartment, nor was she there when they actually entered and got the said contraband/parafenalia. The downside is that they found a gas and light bill in smy name for the address. Another screw-up on my part was that out of nervousness, I told a couple of cops who were interrogating me at the station that I bought thee ounces of weed and sold most of it so I can end up with a half ounce for myself to smoke for cheaper than it usually would be, so I know I kind of screwed myself as far as trying to say it was strictly for personal use.

So here are my questions:
-Is there any way for me to prove that I was not the tenant of my girlfreind's apartment, and if so, will the court have to throw out the evidence that was found there?

Also,
-Even though I admitted to selling marijuana to some degree, will I be able to deny this in court?

Additional info: I am a recent graduate from a 4 year university, I have a job (which I also had at the time of this incident) and I have no previous record.
I have not yet spoken to my attorney (court appointed).

If someone could clear some things up for me about this and give me some direction as to what I should do, I would greatly appreciate it.