transgender

Cis here, but have some experience with this from a few angles (glad to explain, but not really important)

Generally, you can expect discomfort after practice, or extended speaking in a tense state.

The why of it isn't complicated is simple enough, but not obvious. Everything we do with our voices relies on tension in our vocal cords. To apply that tension, we use teeny tiny muscles in and around the cords.

If we're speaking in the range that's "natural" for those muscles, it takes less effort. But, you'll eventually get those muscles sore and tired even then. The more we diverge from that range, the more tension gets applied, and the harder it is to maintain, so even after years of practice, there's still going to be faster fatigue than there is at our natural tone.

Singers run into it more than public speakers because they need to work outside that range more often, but if you do a lot of speaking where you have to project your voice or modulate it, you'll get the same kind of strain singers do.

Warm, soothing beverages are the typical comfort choice. Teas are better than coffee, with herbal teas that are low in tannins being better than actual tea. Add in a little honey to help coat the throat and stimulate mucous production, and you get quick, if transient, relief.

Anti-inflammatories are your best bet for longer term relief. NSAIDs are going to directly relieve any swelling, on top of pain reduction. Some folks favor an acetaminophen and ibuprofen (or ibuprofen related drug) combo because they come at the problem in different ways.

You will experience a decrease in severity, and an increase in stamina, eventually. I can't predict how long because a lot of it depends on how far you are from your most relaxed tone. If you're having to push your voice a lot, it's going to take longer to get used to the effort.

But, your speech therapist should be able to help guide you with good exercises to keep you relaxed during sessions, and with aftercare hints specific to your needs.

Until then, when you're practicing on your own, or you're speaking regularly, try and keep your throat loose and keep your breath flowing gently. The less effort you put into each sound, the less it strains things.

Also helps, imo, to do less with the cords, and more with the tissues above them, when you're trying to raise your pitch. It lets the "gravel" in voice come out as throaty instead of chesty and rumbly, more like Lauren Baccal or maybe Bea Arthur. But always listen to your therapist, not randos online.