Well, today was great... I love betrayal.
So, my girlfriend and her best friend, they are basically sisters... Or at least were. They did everything together, lived in each other's houses for weeks at a time, their families practically adopted each other. And her "sister" hates me because my girlfriend isn't spending enough time with her because I'm in the way. (Even though they still see each other every day, and sleep over half the week.)
My girlfriend has been stuck at home for a few months taking care of her baby brother from 6am to 6pm every weekday because her mom doesn't want to pay for a daycare. So, during exam break I went over to her place every day and take her out on a date, to the zoo, or a restaurant, stuff like that. And we brought her "sister" and baby brother along, because her "sister" refused to let us go alone, and we couldn't just leave the baby home alone.
We had to keep it a secret that we were going out though, because her mom detests me to the point where she would rather have her daughter spend 20 minutes walking home when it's -30°C and a blizzard outside then have me spend a few minutes driving her home. (Not even exaggeration, she got in trouble for getting a ride with me...)
So now her "sister" went around telling people we snuck out and that I was blackmailing my girlfriend into being in a relationship with me by threatening to tell people we snuck out together. And probably a bunch of other nasty lies too, I'm not sure.
And now everyone who knows my girlfriend hates me, because of these rumors, and my girlfriend and her "sister"/bff really don't like each other. And my girlfriend is in big trouble from her mom because she knows she snuck out now...
Now no one who goes to my church will even talk to me. I tried getting a ride home from a winter carnival thing they had at the church for about 80 youth, and I asked a kid who lives a block away for a ride, he refused. I asked another who lives nearby, he just glared and walked away. So I asked a really nice old teacher who was giving my girlfriend a ride, and he ignored me. I asked again, he still ignored me. So my girlfriend asked if I could get a ride, and he finally agreed.
When we were leaving, he tried to drive away without me and so I didn't have time to put my coat on... Then after he dropped my girlfriend off at home he turned on the air conditioning in the car so I would be even colder.
Some people won't even talk to me, they ask my girlfriend to talk to me, and ignore me when I reply until my girlfriend tells them what I said. And it's not like these people disliked me before, a lot of them I've known since I was a baby! I guess they trust my girlfriend's "sister" more than me and my girlfriend?
Also I had a panic attack and punched a kid in the face today. I was talking with my girlfriend and he walked up, jabbed my stomach a few times (I panic when people touch my stomach/sides, and he knew that...) then grabbed me around the hips. So I started panicking and punched him in the face and ran into a storage room on the stage and broke down. I started crying, and hyperventilating... My girlfriend came and helped me calm down, but it wasn't fun.
I would recommend you to debunk those rumours ASAP, make a stand for yourself and explain how terrible of a situation you are in life right now. Talk with your girlfriend and ask her to support you in your stand. If you don't swear a lot, a couple Precision F-Strikes should give some extra weight to your words. If this goes wrong and they say something terrible such as "You wanna kill yourself? Do it, makes us all happy," you should get the police involved.
Seriously, nobody has permission to spread false rumours about you, or anybody. And if you don't act upon it, nobody will.
My girlfriend has already tried to debunk them, but it didn't work. If they don't believe her, why would they believe me? Also, I've never said a swear in my life...
People like that probably aren't deserving of your time. Anyway, sounds like you tried to be nice about it and it didn't work. Just because she's your girlfriend, doesn't mean you have to be around those people. Make the time you spend with her and the time she spends with her other friends separate. Don't bring people like that along on your dates. Better yet, don't interact with them at all. Just because they're her friends, doesn't mean they have to be yours. It would be nice but if you try and it doesn't work then there's no harm done and there's nothing wrong with making that clear.
Regarding the other stuff;
Do you have to go to that Church? Find a different one if you don't. I'd drop the place in a second if people there treated me so disrespectfully.
Is there any reason you can't ignore or stop being around the other people who've been acting like that? Your time is better spent around more open minded people anyway.
Is the issue with the mom something you can talk out? Hearing this from someone who claims to have never cursed in their life, I can hardly think up a good reason why a parent wouldn't like you.
Getting the police involved wouldn't be my first choice but if things persist, it's probably worth it to make a point that you're not going to let people walk over you. Like someone else said, that's slander. Pretty serious slander in my opinion. Under other circumstances, I'd just confront the person but considering how outrageous and damaging of a lie they made, it's definitely worth considering telling someone capable of taking action what happened.
If it happens once and you don't take action, there's a good chance it can happen again. Some people are just trashy people who do whatever it takes to get their way. The best solution I've come up with is making sure they know you aren't someone who will take the bs lying down. It needs to be clear that if they're going to cause you problems, it's going to cause them just as many problems. That way, even if they aren't morally inclined not to be a jerk, they'll be inclined to do so out of self interest.