Urinary Problems (Not a UTI) - Male

I am an 18 year old male, and the last few weeks or so I have had some urinary problems. My doctor ran a urine test and assured me it wasn't a UTI, but had given me some pills to kill bacteria anyway. Here are my symptoms:

- Feeling like I have to pee every 5 minutes (eventually going like 10-20 times a day)

- Weak stream, also sometimes feels like there's retention so it takes longer

- Urine is a little bubbly, sometimes a lot and sometimes a little.

Additional symptoms:

- Sore throat

- Abdominal pain/bloating

- Back has been hurting in the morning a lot

I drink more than enough to surpass 8 cups of water a day and I eat pretty healthy as well. There isn't really any pain or discomfort when peeing, just the symptoms above overall. Any ideas?