Having candida, ureaplasma, and another urinary infection. Noticed a smell like 'fish'. Taking perscribed medicines. Anything additional to do?

Probiotics. If you are being treated for vaginitis (mixed, from your description) then that usually helps restore normal ph balance in the vagina to rid the fishy smell. Some women find help in decreasing the frequency of vaginitis by taking a probiotic, or acidophilus, or garlic supplement. For women with recurrent vaginitis there are longer regimens of medication that can be used as suppression therapy.