Rosemary is a COOL weather loving plant. Can do fine with partial sun or full sun. Well drained alkaline poor(in nutrients) soil .. I find it a maintenance free herb outside in the garden.

'What can I do to fix it?'

I would put it outside asap. It will need hardening off i.e. put it out for a short time and bring in at night. Increase the time outside a little each day. I don't think it has any disease. The problems look cultural rather than physiological.

Thank you both! I put my rosemary out yesterday afternoon and will work to get it back outside.