Need advice regarding ongoing online harassment

Not sure where to go with this so I’m asking for advice and bear with me if this is all over the place but help would be greatly appreciated.
Location: Tennessee

So for about a year now me my girlfriend (both 20) and my 2 kids have been getting constantly harassed my my mother-in-law mostly online, but to sum her up she’s a horrible person whose lost custody of all 7 of her kids and has nothing going for herself, my girlfriend has tried to have a good relationship with her in the past but it’s just not possible. Anyways it all started when my girlfriends sisters baby died (her mom HATED her sister so a reason I’d have to make a whole separate post on) we also didn’t get along with her sister but decided to be there at the funeral and when she found out that’s when they fell off pretty badly. It was a huge argument which lead to her mom making up horrible lies about my kids claiming that they aren’t mine and she even went as far as to fabricate “proof” to make me believe that my kids weren’t mine (which I actually did believe and went as far as to take a dna test).

But ever since then it’s been constant online harassment from everything to making TikTok’s posting my children and me, fake accounts telling me they weren’t mine and I know it, sending people to knock on our door, ordering pizzas to our house, and they even called cps on us saying our kids were getting beat by us which opened a whole case on us. I could go on and on about the things she’s done to try and bring us down but the point is we are sick of the harassment especially involving my kids

We have also already called the police 2 times, the first time was when they sent those people to knock on our door we called them immediately but they left when they heard sirens. The cops told us when we got there that there wasn’t anything they could do since they didn’t do anything to us in person. So that’s why I’m here now wondering what I can even do at this point.

I know I missed a lot of details in this story just because it’s all way to much to type out so if anything doesn’t make sense please ask, I’m really desperate to end this once and for all, thanks in advance