I am having trouble with the grief of losing my mother in January to dementia. Then in February my very best friend died of cancer.

Try the book Healing After Loss, by Martha Hickman. You read only one page a day for a year, and it just helps walk you through grief in small, manageable bites.

If it doesn't help, consider getting some therapy beyond just the grief group. It really can help. Keep in mind, though, it hasn't been very long, and it's tough to recover from grief when you haven't really finished grieving yet.

I am so sorry that you are having to deal with the loss of 2 very important people in your life. Grief is hard. I know. But you must remember that it's only been a few months since you lost them both. It will take a lot longer than that before you start to feel more like yourself again, so please give yourself some grace during your grieving process.
My husband of 26 years died 7 months ago, and I'm still having a hard time with it. Just when I think I'm having a pretty good day, something will trigger my grief. It could be a song, something I've read, or just walking by his picture on my wall. It doesn't take much. But I don't beat myself up over it. I just let it come, and I let myself feel it,(which is so important)instead of stuffing it down. Everyone grieves differently, and everyone's timetable for grieving is different as well, so just take your time through the process, as your mom and friend deserve that much. God bless you.

I am so sorry you are going through this.
Grief at any time is difficult but during a time when we are supposed to keep our distance, no hugging makes grief even more difficult.
I can say all the things that people do..they are out of pain....they will not suffer any longer...but that does not help the ones left behind.
Honor them by doing.
Was there something that your mom and your friend liked doing? Can you volunteer in their honor?
Dealing with 2 losses so close if you feel like you need to talk to someone ask your doctor for a name of a therapist that you can talk to. Sometimes talking to 1 person helps when a Support Group might not be enough.
Just give yourself time. How much time?...As long as it takes is the right answer. No one should have a timetable on grief.

There is no reason that you SHOULDN’T be having a hard time. I hope people around you are not insisting that you should.

I’m so sorry for all of these losses.

Perhaps consider a GriefShare group. You can Google them. Our local group is meeting in-person.

Best wishes.