i was told today that i will miscarry...

i just found out this morning that i am miscarrying. they believed i was between 4-5 weeks at my first US, but based on my lmp i should’ve been 7 by now. my hcg only went to from 3316 to 4706 in 48 hours. i started brown spotting last night, ultrasound this morning confirmed the baby never started to develop. i don’t know nor do i understand why this is happening, we tried for two years, this was my first pregnancy. i can’t believe this. i just want to shut myself away and cry forever. i had a feeling something was wrong. i’m not sure why i’m posting this, i just need some sort of closure. i’m so scared the miscarrying process is going to hurt.