Choosing tri bike

Hey all. Aging triathlete here. Purchased my one and only tri bike about 14 years ago. Sort of an impulse purchase to be honest. It’s been fine, but I think it’s time to consider an upgrade.

Any tips on how to get smart about choosing a bike? I know fit is the most essential part. And I understand that different bikes will fit differently. But I’m not sure how to go about evaluating those bikes relative to me. I’m considering getting a fit in advance of buying a new bike so I can get a sense of what type/brand of bike might be best for me.

Anyway, any advice, articles, hints are welcome.

Yours in suffering,
Pete