Why is queer an okay slur but the others aren't? I don't like the word and I consider it an insult.

"Queer" was originally meant to be an insult against LGBTQ+ people. The literal meaning of "queer" is "strange", it originally was meant to make LGBTQ+ people feel different and excluded. However, the LGBTQ+ community has started a process of appropriation of the term, depriving it of its original connotation and claiming the right to use the world with a positive meaning. Right now, the community uses it with pride, it transformed it from an insult to a sign of cultural identity. It's ok not to use the term if you don't like it, but it is not meant as an insult anymore, it know stands for something entirely different.

queer is generally not considered a slur because it is used as a sexuality, like how some people use 'gay' as an insult even though its actually a sexuality. the other slurs targeted towards lgbtq+ people aren't actually something you can identify with (like you can't respond to someone asking what your sexuality is and say "f-word" (I'm not going to say it obviously but you get it). since queer is something used as both an umbrella term and something people identify with it isn't a slur in that sense even if people do choose to use it as an insult.