Hello again, mate.
I'm not medically trained but would think this last rise is more likely to be prostatitis than PCa. During the periods between prostatitis your PSA seems to have remained relatively stable.
You do appear to have a slightly over anxious disposition, which is not ideal for AS. However, whatever treatment you have, PSA anxiety will always have to be dealt with. In fact, me and many others on here, felt PSA testing was easier to cope with on AS than it was following further treatment. The fear of BCR can be worse than the fear of being diagnosised with the disease.
You're nearly two years on since your first MRI biopsy, so you are due follow ups. The results will dictate whether you stay on AS. I suspect that you will. Anyway, whatever the results, by being on AS, you've at least avoided the risk of any possible further treatment side effects for the last couple of years.
Good luck with the follow up procedures and please keep us updated. 👍