Wanted to stay anonymous and therefore , respecting your decision.

I cant say that i fully understand what you are trying to convey out of that long text but from what i can see is that you are having loads of dramas in your life rn . Its good that you obviously show care towards your best friend but maybe what she really needs right now is space rather than moral support . Dont get me wrong , but yes , moral support is good , however it may cause her to feel oppressed due to you constantly asking her if shes alright .

Some people would prefer to quieten down and have some space to think. Its good to know that your best friend is now going to see a counselor since a counselor should be much more better at giving advices , rather than a nobody like me .

For the problem regarding you and your bag , i think you should be the bigger person to let it go and not hold grudges . Though your senior may be rude since he/ she layed and slept onto of your bag , however , he/she still kept it for you so thar you dont have to squeeze it underneath your legs and make your whole journey much more unbearable other than the limited space you are given .  Yes , you may think that its a big matter but , i suggest that you be more open minded about it and let things go.

About your other best friend , firstly , is she really your "best friend" ? If you really dont like her and her guts , be firm about it and tell it straight into her face so that she would know to never bother you again . It may be hard and awkward , but i guess its the fastest solution to get her off your back .  Also , if she keeps acting up to your best friend , defend her , be on her side no matter what .

Just always be there for her .... good luck