I know there are some other posts about this, but I cannot make much sense of them I am new to apex and salesforce, learned a considerable amount in the time I've been working with it, but right now Im up against a wall, and its BAD

I, for whatever reason, could not make opportunities in my sandbox, could not figure out why, but wanted to try this trigger. So like a fool I put it to production. No nobody can create or edit anything [a Work order - custom object we use to project details]  We NEED this to work. My company is at a halt, I NEED to remove or disable this trigger asap.

I tried to mark it as inactive in sandbox, and push it to production, but it says "Average test coverage across all Apex Classes and Triggers is 72%, at least 75% test coverage is required." I have NOO idea what this means and no time to figure anything out. Needless to say - I am freaking out. PLEASE someone help.