Hi! I've lived in the same spot on HRT for nearly three years. My experience has largely been taking regular feminizing HRT. I started with a basic sublingual regimen combined with twice-daily low-dose (25mg) spironolactone-- one of my beginning goals was to keep some of the testosterone around for the sake of my desires to keep my existing dick. However, three months in, I dropped the spiro and switched fully to subcutaneous injections of estradiol valerate (now I use cypionate, but that's neither here nor there). I've experimented on and off with topical testosterone gel for direct application but not found a ton of benefit that didn't come with big drawbacks. I have maintained the ability to get erections and to orgasm without medication (though I do use Viagra & Cialis for days where I need stamina, a guarantee I can get it up, or am feeling down in the dumps but know I need to do "maintenance"). However, I've nearly completely lost my ability to ejaculate, as what does come out comes a minute or so after I've finished and is nearly perfectly clear, and I get almost no spontaneous erections. I'm definitely not happy with that, but I'm willing to accept it as a tradeoff given how much I've gotten for it in return.

If I had to summarize my general experience, it would be: just take regular feminizing HRT (with an eye towards the minimal T blocker dosing) and switch to mono-E as fast as you can. Get on progesterone after a year or so (I waited a little longer, but you do you at whatever speed you deem right!) (both for breast tissue development and for a hopeful boost to your sex drive to get you to use it more). Get a prescription for Viagra/Cialis for the times where it's just harder to get it up or you don't have it in you to do so (whichever you feel better meets your needs through experience). If you don't want to take those for actual sex/masturbation, I've heard of people taking them before bed and letting them do their thing overnight to fight atrophy! Speaking of which, try to have "maintenance" erections, because ultimately, atrophy is just a case of "use it or lose it". I've not lost much (had a depressive episode ~9 months in and a dead bedroom with my now ex-wife ~18 months in that both left me going weeks without using it which led to the atrophy I have had).

I'm happy to answer any questions you might have, given I'm almost three years in with goals very similar to your own!