I'm going to pretend to be supportive.
What does pretending to be supportive look like to you?
It's someone who seems to be there for someone else, but they are really only interested in themselves.
While it is important that your needs are being met, it is not good to only pretend to support someone. Being genuinely supportive of others will make you feel better in the long-run and will make your friendships more fulfilling.
I'm already good at faking it. I don't think I could change my behavior now.
Although I'm sure your disingenuous support is still helping people, it would be better if you were just honest and acted like yourself. If you can't bring yourself to genuinely act selfless and help others, it would be best to just be true to who you really are. People will respect you more for it.