Dying melon vine :(

Dying melon vine :(

I have a melon vine that has produced two small fruits, neither of which are ripe yet. However, the older, bigger leaves have been getting what look like squiggly yellow patterns that increase until the whole leaf is covered in yellow. The leaves eventually die. The younger, newer leaves seem to be all right, but as they get bigger they usually succumb to whatever it is that is killing the older leaves. Is this some kind of fungus? The dying vine is making me really sad. Also, how do I know when a melon is ripe? I'm thinking that maybe I should pick the fruit at least. Thanks in advance for any help.
Weed (???) ID?

Weed (???) ID?

My new home sweet home.

My new home sweet home.

The flying insects have discovered my zinnias!

The flying insects have discovered my zinnias!

The very first thing I planted this season.

The very first thing I planted this season.

Summer Blooms

Summer Blooms

Bugs in my dirt!

Bugs in my dirt!