Concerned about possible cdiff

Hello, I am very concerned that I may have cdiff.  Here is my history, almost 6 weeks ago my 2 dogs got in a fight and I was accidentally bitten and developed cellulitis.  The bite was on my leg and is now healing well, unfortunately I went through several anitbiotics for this infection.  These included kelfex, cipro, rosephin, bactrim and clindamycin.  I went through so many because I was allergic to a couple and also ended up on steroids for 2 weeks.  About 6 days after being off all the antiobiotics I started developing stomach & abdominal cramping along with diarrhea about 5 times a day.  Well after a couple days of this I went to ER over the weekend because my cramping was getting pretty bad and I was concerned since my antibiotic info said to check in with doc if such symptoms developed.  ER doc said he was concerned about cdiff, gave me a script for flagyl just in case, said to get a stool sample in and check in with my doc in a couple days.  Well after a couple days on flagly my diarrhea improved and my cramping was going away.  Unfortunatley I devoped thrush from the flagyl and was getting pretty bad headaches from on it.  On the 5th day of taking it I got very dizzy and weak & went back to ER.  I was dehydrated and potassium was kinda low, so they gave me both & also told me to quit flagyl because of the side effects was having & to wait on test results from stool sample.  I actually brought sample in that night and it was left sitting out for a hour or two even I kept asking if it shouldn't be sent to lab.  Well that test came back negative for cdiff, but my regular doc thought it might be wrong because I was on flagyl at the time & sample was left sitting out.  So I sent in another sample (was off flagyl for 4 days at this point) & after a couple days it too was negative, it has been a week now since this and my regalur doc is working on a referral to a GI doc.  She doens't think this is cdiff since 2nd test was negative, but I am concerned because I am very weak, still fighting diarrhea 4-5 times a day, stomach cramping, some nausea and have lost 12-13 pounds in a couple weeks.  I just feel like I am not getting better, have even went to ER a couple times to get fluids because of dehydration - a couple of the docs there said this could still be cdiff because the tests are somtimes wrong.  I did have a ct scan of abdomen with contrast and it was ok, also none of my blood tets has shown an elevated wbc.  I'm just very worried that this is cdiff despite negative culture test and I am not getting the treatment I need, I don't want this to get serious if it is.  I am going to talk with my doc again tomorrow and see what she thinks & what the status is of the GI referral.  Any advice?