I'm sorry to hear about your mom. Sometimes it doesn't matter what we do, life is still very hard.
Don't be afraid to let your emotions out. Talk to your mom, tell her that you still love her and that you miss her. She still lives in your heart, and she will hear you.
Otherwise, just give yourself time. Be kind and gentle to yourself, just as you were kind and gentle with your mom. The past few months were her time for care, now it is your time for care.
I know it's hard, but try to get some laughter in your life. Laughter and humor are healing - you need them. Even if you have to force yourself to laugh at something, go ahead and do it. You will slowly find the laughter becoming genuine, and then you will be able to start healing.
Sincerely,
Tre