No longer having either of my two, I can empathise with you. That said, there is life after testicles - honest!
The "secret" to this life, is getting your TRT right. I think it's good that you are already on TRT however you may need to boost the amount you receive - I am not an expert here, just a "dumb user". As you'll have read, getting the right amount (for you) is key to a good/normal quality of life. I'd suggest getting in touch with a (male friendly) endochronologist and get your levels measured again.
In terms of prosthetics - that's a personal choice. I choose to have them and I wouldn't be parted from them... but it's a personal choice. If I couldn't have them then I think I'd be fine, but now they are there I can really see how they help me both physically and mentally. Yes I know they're not real, and yes I am quite happy to talk about them with other people (so they also know they're not real), but over the past couple of years they have become very much part of my body. And better than that - they won't let me down like my originals did!
Good luck in your choice, and remember you can change your mind later and have them added/removed as you see fit.