I can help, but.... it's not easy, cheap or convenient....
We lived with those little &(^%$%^'ers for 2+ years and I finally lost it when I was cleaning 10 of them out of the windowsills every morning.
We had an exterminator come in over those years and spray and it kept the numbers down a bit but for some reason last March they just exploded in numbers and invaded the house. So I called Terminix.
The Terminix man took one look at the numbers (like I said, 10+ in the windows) and said we needed a drain service.
Called Horizon and they came out and put a camera down the sewer pipe.... ohmygods what I saw was absolutely disgusting. Swarms of those little ^(^%(%'ers in the pipe, just waiting for their day to come into the house. I screamed. (No joke.)
Based on that camera scope, Horizon said the sewer pipe had cracked thanks to tree roots and the little joys were breeding in the soil around the pipe.
The ONLY way to get rid of them for good was to dig up the pipe, take out the contaminated soil, replace it with gravel, and replace the pipe. We're on a concrete slab (no basement) so this meant drilling through our family room, laundry room and bathroom floors to fix the problem.
$11,500 and one week later (they got us right on the schedule because we were "such a bad case"), the drain pipes were replaced. When I walked back into the house there was a carpet of the little %^(%$'ers on the floor. *shudder* I scrubbed the place for 3 days before I'd let my daughter come back (we stayed with family).
They kept appearing for a couple of weeks, but about 5 weeks later they had run their cycle and a year later we haven't seen one single little joy. Yay!
And Horizon got us in touch with an insurance adjuster who was able to get our homeowners insurance to pay for the repair, woo! (I strongly advise getting an adjuster, they really fought for us)
I saw one at a friend's house last week and my heart sank for her.
I hope that helps... Sorry this is so long.
Good luck to you, MissMommy, and big hugs. I understand the stress you must be feeling :(