There are widows/widowers support groups. Grief or just social. A friend of mine is a widow and she met other widows through grief support group. My daughter used to rely on support group specifically for young widow/widowers, it was a blessing, really helped through. Also I don’t know if at the end your dad was under the hospice care, if yes they provide a year long free grief support for families. Usually group sessions. Finding like minded people might help

When my mom died I had a horrible time the first year, not just because of mom but my brother and I had to deal with our dad literally going nuts, we couldn’t even grieve as we had to deal with him , I didn’t find therapy helpful, i didn’t find talking helpful, but I was recommended a book about grief. If you want I’ll send you a link. It’s a book where you read a passage a day.