Is there anything I can do to help my plant from p...

Hey you can try to tape it or bend it together. For the next time cut the stemp a lil bit higher. Because the main trunk pulls slightly inwards after being cut.✊dont give up on her :)

As you are doing a mainlining plant, is it your sides splitting it? If so, do not stem split. You need to build branches. Something like a Y shape or a bamboo stick, stick, pole etc and split it and brance your 2 main stems from your mainline plant. As the issue will just get worse as she gains more weight Also, if you are growing in a tent. You can make simple braces from string and holding up weight The 1st option is best. As if you brace it with string. It'll be hard to move for defols etc. So braced from your soil up to your 2 main stems.

you can use that opportunity and cut the stem a bit more. If you dont want to, i can understand but i would still put tooth sticks in there. Thats a trainingtechnique but forgot the name. You can also just skip on that and simply repair it. Before you put toothsticks or if u simply want to repair. i would apply one cabletie underneath the damage so it doesnt get worse and up above you can use a thick thread, bind it around both branches and the middle top inbetween like an 8 or simply around both branches, you can put a lot thread there till it looks like a ball. so press the 2 branches together that will pressure the wound together by itself.

Provide support for the branches, to reduce stress on the main stem........i.e., tie the branches to (bamboo) stakes.

Paper masking/painting tape , not more than few lairs, after 2 weeks take off. That spot will heal during that time and open wound will be covered, so all infections/fungus/bacterias cant get into plant.