Macbook Pro having trouble finding HP Photosmart wireless printer signal

This is a desperate cry for help! Is there anyone who can help me to reconnect my Macbook Pro 15 (late 2011) to my HP Photosmart Plus B210e wireless printer? I've been searching on the forums; I've googled the heck out of it; I've done exactly what the Apple help topics said to do. We had just gotten a new wireless modem in the house, and it was easy-peasy to get the printer connected to that, and my husband can print from his PC just fine. I've had trouble in the past with the Mac losing the connection, but it's never been this much trouble to find it again.

I'm using OS X Yosemite 10.10.4. No updates are available. When I go to System Preferences, then Printers and Scanners, then + to Add Printer, it opens up a window with three tabs: Default, IP and Windows. Even after shutting down my computer and the printer, unplugging the printer and waiting 30 seconds, plugging it back in and turning both on and waiting 5-10 minutes for them to talk to each other, I get nothing coming up as an available printer. I've done this probably 20 times in the past 3 days.

There is no button to hit to "scan" for the printer signal. The only thing I can do is enter the printer's IP address then hit Add. Up comes a message that says "Unable to verify the printer on your network - Unable to connect to '(IP address)' due to an error. Would you still like to create the printer?"

So I say Yes. Then it shows the printer by the IP address under default printer with a green light, saying it's idle. It now shows the printer on the dock again, and when I open up the job in the queue, it says, "Communication Failure: The computer is no longer able to communicate with your printer. Turn the printer off, check your printer connections and check for printer errors, and turn the printer back on." But yet, the Mac was able to communicate with the printer and see ink status, etc., which it couldn't do before.

This is SO frustrating and such a waste of time! What in the world am I missing??!

Next step is I'm trying to post to the Apple Community Forums (signed in with my account) to ask for help, and I get this message:"You are not allowed to create or update this content"
Why not? It gives me no reason, so I don't know what to do with that.
So then I'm praying and I decide to ask for an exception to a charged call from Apple Tech support, and I kid you not, "Jesus" answered and granted me the exception. His name was literally Jesus! (Hey-sus, Spanish pronunciation) But even Jesus was not able to "heal" my problem. Jesus was stumped. (That was really disheartening!) We had Mac-printer communication and were able to print a test page from the HP utility site, but not from say, Open Office or the printer queue - we still get that same message. I can still call back under the exception case number though. We did a reset with Control-Option-Shift-Power, then did a Command-Option-P-R right after hitting the Power button, holding them through 3 startup chimes and letting them go. We checked for malware and found none. We did some of the same steps listed above over a couple of times.
But problem is not solved. Aye-yi-yi!