How to fix my family tree?

No, unfortunately I didn't make any back-ups or use save as. Do you need to see all the files within my save folder? cause if so I might have to take more than a couple of screenshots. 

Here's some of the more recent ones. there's also 3 extra folders in my saves but none of them belong to MCCC

@SoggyPinata01 

Unfortunately, you tried to do something the game can't handle.  You can have only 2 parents for a given child in the family tree.  I use MCCC too and found that if you have a same sex couple, the game itself will show both sims as either mother or father of the child (2 mothers or 2 fathers).  If you try to change that with MCCC, the mod insists on allowing you to designate only one mother or one father, which messes up the family tree and disconnects the child from the other parent which is what you've had happen.  The easiest way to fix that and get the relationships back to what they're supposed to be is, as @crinrict suggests, go back to an earlier version of the save from before you tried to change it by using the recover save option.

Depending on when you made the changes, I see 2 versions of your latest save (22- Jan 6:04 PM) that go back around 22 hours (21-Jan 8:18 PM).  If you made the changes since then, you should be able to recover.  If you made the changes, before 8 PM yesterday, then you're probably out of luck unless you have another full save made earlier.  So, I suggest you recover that one if you can.  Hopefully, you haven't saved again since posting and wiped out that version.

If you don't know how to recover a save, just go to the Main Menu, hit the Load button.  When the panel opens with the list of saves, look for the Recover button on the right side of the panel next to the Delete button.  Hit it and follow the directions given choosing the version of the save you want to recover.  A new save that has Recovered in the name will be created.

I'm not sure you can fix the problem with MCCC but don't know for sure.  If you use Discord, there is a MCCC support Discord server that offers help for issues like this in their help channels.  You can ask for help there if you so choose.

Hope this helps.

Yeah, the 21st Jan save is after I already made the mistake. That's why I was curious if there was any way to recover or find save files that ARENT in the list of 'recover save'. I'll pop onto the MCCC discord and see if there's anything to be done, but man I really wish Sims 4 had a bin or something for old saves. I understand why they don't, but I really wish they did

@SoggyPinata01   Hi!  Just to clarify, did you use the MCCC Relationships menu to add the mother relationship that first time?  If that's the case and if you just want to change the relationships back to how they were before you made the change, then perhaps you could try using the cas.fulleditmode cheat and changing the relationships back to how they were in CAS. 

Just in case you haven't used this cheat before, try these steps.

1. Load your household in Live mode

2. Press ctrl+shift+C to open the cheat console

3. Type or copy/paste cas.fulleditmode

4. Press enter (you will not get a prompt that this cheat is active)
5. Take the household into CAS

6. Click one of the child sims

7. Change the relationships for the Mother sims

8. Repeat 6 and 7 for the other child sims

9. Once you have set all the relationships, click the check mark in the lower right to get back to Live mode.

Now double-check their Genealogy to see if everything is back to how it was originally.  Please come back and update if this worked or not.

already tried fixing it in cas with cas.fulleditmode, and while it may have fixed one of the relationships between the mother and the child, either of the other children can't have that same sim set as a parent. Also one of the brothers is set to being the cousin of one of the other children when I change them in cas?? which I don't know why it does that when none of the parents are related (I checked in cas and MCCC, they have zero relationship bits or family bits). also changing any of the mothers to 'able to make pregnant' still doesn't let me set any of the kids as having 2 parents. 

I checked and yes MCCC does use an auto-save feature, but unfortunately I didn't have it turned on so it didn't save anything before I lost the right save file. However I did some playing around in game and each child successfully has 3 mothers- but that is just not reflected in their family tree. And I don't think I can fiddle with any more MCCC settings or UI cheats without breaking all the relationships again, so I'm going to leave the family tree broken and just make an external family tree instead of using the in-game one. Thanks for all your suggestions, now that I know MCCC saves are a thing I'll be using them all the time😳