How to correct my trolling motor mounting setup??

Hey fellas quick question == I recently purchased and mounted a new min kota trolling motor on my 16' MonArk. The troll has 55 lbs thrust, and I mounted her to my bow as indicated in the picture. What I did not account for is that when I crank the troll, the deck that I mounted her to would flex and bow. After a test run the other day, I am not comfortable with the amount of flex in the decking each time I stepped on it.

Any recommendations on how to efficiently correct this hitch would be greatly appreciated. Please send pics and detailed instructions, not assuming that I know what the heck I am doing...

A lot of boat makers have wood under the deck of the bow.

If you have access to the area underneath the deck where the TM is mounted, just get 1/8" or thicker aluminum plate/walmart plastic cutting board/alum angle iron/etc and use it to support and strengthen the decking. If you don't have access, you can make access via cutting a hole and then install a hatch cover after installing the deck/TM support.

MK also makes a couple TM mounting plates that may work in your situation as well.