Prozac 40 mg not working as well, should I go up on dose, or switch to new drug? I have already been

I agree with veterinarian vet. Whatever you do, run it by your Health Care provider or pharmacist first.
Then try to stay as far away as you can from benzodiasipan (benzos) they work but very easily dependent on, (Hooked).

Best regards
Kevinb1953

Hi, Kashi!
You could go as high as 80mg of the Prozac (fluoxetine) if you want to give that a try. Remember that you need to give it at LEAST 6-8 weeks for any antidepressant to become fully effective.
After being on 15 ineffective medications I'm surprised that you haven't been prescribed a mood stabilizer (Lamictal for example) and/or a booster antipsychotic (Abilify or Rexulti). If you've had no response you might try Latuda, Vraylar, or Caplyta for Bipolar depression. Also, if you haven't already, you should look into CBT talk therapy as an adjunct to your medication.