I have to agree ...
We've run a few of our newsletters into the ground using a
format that is eerily similar to what you're using ... ( learn
from our mistakes
)
If you have to keep the ads in there for some reason, maybe
they're being paid for?, then put them a little lower down in the
newsletter itself so that the subscribers see content first ... my
guess is that you're getting a lot of people seeing, ad, ad, ad,
and then scrolling to remove without even seeing the content.
The other thing to do might be to keep this type of format once
a week with a few modifications, and send another issue out that
is nothing but content, no ads. If your content is good in the one
issue they get, your subscribers will be more likely to stick through
the ads they know they'll get in the other.