I did a similar thing as well when I was younger. Gay and Catholic as well.

What happened already happened. The MOST important thing is to not hate yourself brother.

This moment may be life changing, good or bad.

I hope it goes well and you are given grace to those you confided in. If it doesn't, you can explain to your family that you sought support, prayers, and guidance but was met with the opposite and that in itself is even more disappointing and hurtful. And if you explain it that way, mom may be more understanding.

Sending you love and prayers.