I had Salmonella once about 10 years ago. Horrible stuff. I did some research on it and I found out that:
You should not take any medicine for this, it will work out by itself. It takes time to rid your system of it. You can have trouble off and on for up to 1 year. Each time you have a spell of it the recovery time is shorter until it is gone.
I took no antibiotic nor anything for my stomach for it and was very careful what I drank and ate each time it came back (maybe 3 or 4 times). It lasted about 8 months to finely go totaly away.
Good luck
sometimes after a salmonella illness you can develop irritable bowel syndrome, so that might be the cause of your ongoing problems. godd luck