If you main support in bronze, play more aggressive ones. Thresh, Blitz, Alistar, Braum, Taric, etc. Hell, even go for kill lanes with Zed, Xin, Irelia, J4, Talon, etc, specifically because your ADC may not be that reliable. Its bronze. Literally anything works if you're better than them.
Bronze players often do not know when to play offensive/defensive. Abuse that, then abuse their map awareness (hence the kill lane picks being viable in bronze).
Another option is simply moving out of support until you start winning a little. Starting at the lowest common denominator for a role is a great way to climb because it allows you to grow in another dimension that you have little experience in, and if you start improving that way, you will quickly pick up steam and get to an MMR you can consistently play your main in and win again. Plus you have the benefit of having another role you can pivot on at your typical MMR.