Ok. My cousin is actually going through this right now, so I can give you some tips on how to handle it.
If you ever feel like you can stand, you need to lie down immediately, so you don't pass out. Sometimes, you may feel like you can't stand because your sodium is low, it would be wise to keep little soy sauce packets in your pockets, or with you at ALL times.
It may be hard for you to get up in the morning and stand. If that is the case set your alarm for 30 minutes earlier than when you need to get up so you can begin getting up. So you will SLOWLY rise up a little then stay until your heart stops racing. Then you do it some more until you are fully sitting up. Then you will go to the end/side of the bed and you will elevate your feet slowly up and down until you feel you are ready to stand.
If you feel any other problems, first, let your mom know, ofc. Then let me know and I'll see if I have any tips on how to help
Also, I'm so sorry about your dad. I know what its like to lose a loved one.