A couple thoughts:

1. Is this coat of arms one that you are legitimately entitled to or a "bucket-shop special"?

2. Designing a tartan based on coat armor doesn't usually result in a nice tartan. I'm sure others' opinion will differ.

A final thought:

Perhaps press the "pause button" on this. Spend the next year learning about heraldry and tartans and then pick it back up with a more informed sensibility.