I'm not pleased with my results. I'm not satisfied with my results. I'm not happy with my results.

My results are displeasing. My results are a let-down. My results are disappointing.

I would not say it is too old fashioned. It sounds very professional! You can also say "I am disappointed with my results" or "I am not satisfied with my results". However, what you said is perfectly fine.

displeased by*; what is a* more natural way of saying it. "I wasn't happy with the results."