I [18 M] just want to confess to her [18 F] but just need a push

(Throwaway because she uses Reddit as well)

I have been crushing on a girl, we'll call her Amy, for a while now. Amy and I met while participating in the same school club over a year ago, and started getting closer a few months.

At first I didn't think much about Amy, but after we started meeting up outside of club activities, I started to develop feelings for Amy. I never really thought it would happen (because I never thought Amy would be my type) but it happened. I guess the heart knows best.

A few weeks ago while Amy and I were out drinking, she came back to my place and spent the night. We didn't do anything besides hold hands the whole way back (because it would be wrong since we were drinking)

The school club is very important to the both of us, and I don't want to ruin that for us, however I feel like if I don't tell her how I feel, I will regret it for an extremely long time. Is it greedy for me to confess?

I guess what I'm looking for is just some advice, inspiration, a push, or just guidance on this, I really care about her and like her. Thank you!

tl;dr: Got close to a girl in the same school club, started liking her, don't want to ruin club-relationship, but feel the need to confess.