So lost 😢

I had a miscarriage at around 12 weeks in June 2018. My babies heart just stopped beating. Doc found evidence of chromosomal abnormalities (Aka they have no clue why this happened) I just had my 2nd d&c at almost 9 weeks for my 2nd loss on Feb 18th due to blighted ovum. I am 30 years old. I have other children. I dont understand why this is happening. 2 completely unrelated losses. Doc basically says bad luck and we can try again but I am terrified. We feel in our hearts that we are supposed to have one last child but I am torn. I dont know if I should just give up and tie my tubes or not. I just dont want to go through this pain again. My heart cant take much more. My faith is being tremendously tested and I am just crushed down to my soul. I wish there was a hand book to life. A manual, if you will. Do this, do that. Dont do this, dont do that. I am genuinely lost.