Seeing that people don't choose their sexual orientation, it is improbable that they can decide to change their sexual orientation overnight. Psychiatrists' and psychologists' attempts to "heal" LGBTQ+ people didn't change their sexual orientation. These "treatments" may temporarily change sexual behaviour, but they cause severe consequences on physical and mental health, eg., depression, anxiety and self-destructive behaviour.

On the other hand, sexual orientation for some can be fluid throughout their lives, e.g., a bisexual person can feel more attracted to one gender for a while and then to another later on in their life.

Also, someone might discover their sexual orientation later in their life even if they've had heterosexual relationships in the past. This doesn't mean that they didn't love their partner or that their sexual orientation has changed.

Sources:

Interline. (2021). LGBTQ+ myths and realities.

Castaneda, Marina, Understanding homosexuality, keys and advice for homosexuals, their families and therapists.Ed. Robert Laffont, S.A., Paris, 1999