One step you can take is to humbly make amends to your parents and make things right.
for the relapse in their house
Whether they accept your amends or not, is up to them...but you can quickly take positive steps to clean up your side of the street.
Ask for what you need from them and that may be asking them to hide the alcohol when you come over. Tell them you are struggling but today you are working at being sober.
Don't hide in shame...worst thing to do in my opinion. Learning to be honest about what you do and how you are feeling is part of sobriety.
Focus on today.