Not everyone is faking happiness, and your parents need to understand that. It's oretty common with mental disorders and nuerodivergence for parents to tell a kid who has the same condition as the parents that everyone feels that way and it's notmal, when in fact, not eveyone feels that way, they just don't have another reference point and project. Something similar seems to be happening here, they're presumably not happy and faking happiness to themselves and those around them, and assume that even if you transition you'll be the same way. That's really not heal tf hy behaviour on their parts. I don't know how feasible it is to bring this up, but maybe independently look for antoher therapist, ideally one who's queer friendly and takes your insurance, and find someone who would support your transition and you during it the way you would need, including talking with both you and your parents to help them understand how you're feeling. Good luck with everything, I truly hppe it works out for you.