Thinking about that for at least 10 seconds would make you less concerned.
Your bank details are not on this site so how would they be stolen.
Your password may be stolen, that is possible by various means, but lets assume it is stolen. Oh No. Someone will be able to post under your name on this site. What a catastrophe. It will be TEOTWAWKI.
Password get compromised all the time. That is why you should never use the same password on multiple sites and it is recommended that you use a password manager to keep track of them. I host my own password manager and all my passwords are 60 characters long. They may still get stolen but if they do it won't compromise other sites and I'll just change it. On the more important sites, like my bank I also use 2FA. That is where you have two types of identification, one you know, a password and one you have, a mobile phone or pass key. Both are needed to log in.
Now atm this site isn't protected by SSL but I'm upgrading all my sites in content and security and it will be. But it just isn't important tbh.
Be sensible. Look after what needs looking after. You only need to make one mistake.
If you want to know more then give me a IM. This was after all part of my job for a very long time. (Which makes me wonder why I didn't set up SSL years ago)