That's not how it reads. Consider the Law as a description of reality rather than an admonishment to an unattainable ideal. It is, after all, Natural Law. You WILL be forgiven as you find it in your heart to forgive; you DO love your neighbor as yourself. I see it all over the place. That's just how it works, although it isn't always obvious.
Now that doesn't mean that I won't hold perps accountable because I fear God. It does mean that I will do so as I would be willing to be treated had I done the same. There's nothing wrong with that. I will judge as I would be willing to be Judged.
The "forgive us our trespasses" line you quoted is a line from the Lord's prayer,... a prayer to God. My forgiveness isn't what he needs, cause he won't be answering to me.
No, you will be answering to God as you have answered the acts of others. That's what it says. To be as just and merciful as you are able does not mean that you let people walk all over you. It means that one should consider dispassionately the best that can be done because it's simply all you can do. A loving God would ask no more.