Please help calm my nerves

Hello Mamas! I’m writing to see if any of you had an epidural with your first delivery and ended up needing a c section? I had an epidural and it didn’t take the first time(just on about 1/3 of my body was numb) and they ended up having to take it out and do it again because I was going to have to go in for an emergency csection. Now that I’m pregnant again, my doctor said this time they will just do a spinal block for my section and tubal ligation. My question is, is there a big difference and do the blocks also not take sometimes? I’m terrified of getting the spinal block and not being completely numb. Sorry for the lengthy post.