Writing a eulogy for my dad after his sudden passing, was easily one of the most difficult things I have ever done.
My best advice would be to practice, practice, practice. The first time I read it aloud, I had a panic attack. Make sure the first time you physically say it aloud, ISN'T in the crem, or wherever. Read it aloud in your kitchen, sit in the car and do it. Literally do it so often you practically know it from memory. Let the physical act of saying these things become something of a muscle memory.
On the day, give a copy to your vicar/celebrant/whoever, and if you do crumple, they will step in for you. I also asked my most sensible cousin to be my wing-woman. I'd asked her to sit on the end of a row, and be ready to jump up to support, if required. Knowing I had 2 fall-backs helped.
If your voice cracks, or wobbles, that's normal, people expect it. And honestly, I felt entirely "held" and supported by the entire audience. I could almost feel them willing me through it.
Looking back, I'm so glad I did it. So many people complimented me afterwards for my speech, and I'm sure dad would have been pleased.
I am so sorry for your loss. Sending you strength.