There is nothing easy about any of this. Absolutely. Nothing.
With time, you don't think about the severity of the situation as much. But, then there are the moments where you realize that this is the rest of your life. For the rest of your life, you will live missing someone. Missing someone an insane amount... the "it's hard to breathe" kind of miss. The rest of your life.
You get to live the day your baby died... Time and time and time again. If it wasn't hard enough doing it once, you get to do it over. and over. and over. While you get to live it over and over again, you will change the outcome in your head a hundred times. You will wake her up sooner. You will check on her and realize she isn't breathing, and save her. She'll be saved in the ambulance. Then, you realize that it's all the same. The outcome never changes no matter how many times you analyze that day and attempt to change it. You realize this, but yet you still think about the day often and still try to change what happened.
You will attempt to find every single reason why your baby died if you were left with "sudden unexplained death in infancy". You still won't get it. Almost 9 months after your baby died, it will still boggle your mind how your baby could be here, then not be here. It will still boggle your mind that your baby died for an unexplained reason. While you have to stop researching because that starts driving you crazy, you still won't get it. You will know there are mysteries on this Earth that we aren't meant to know. There are things we won't know until we get to Heaven, it still won't make sense and it will not make any sense. You will start to just accept that you will never know, but it will really still just boggle your mind. It will still just not make any sense.
You'll hear your three year old talk about Heaven. Say that he wants to go... or say he doesn't want to go. He'll question why his sister died. Every time you realize that he has had to grieve a big person in his life, it will make you just want to sob. He'll say "She doesn't even poop in her diaper anymore" or "I didn't get to see her go to Heaven" or "Can't we just go visit her". You'll grieve with him and for him... and then you'll realize he is just a little boy and he shouldn't have to do this. If you get pregnant again, he'll use phrases like "when the new baby goes to Heaven..." and that'll just kill you, too. Because to him, babies going to Heaven is normal. You'll check on him while he's sleeping often. You'll thank God every time he wakes up. You'll never be able to discipline him well for coming out of bed 100 times, because your baby died while she was sleeping... and you don't want him or you going to bed mad or frustrated. You'll learn from his child-like faith.
You'll make other mommy friends who've lost their babies. You'll connect with them. You'll need them. You'll thank God every day for them. But, you'll have days you still feel entirely alone. It'll just feel so lonely.
You'll feel crazy. One minute you are smiling, and the next you are sobbing. One day is easy to be around babies and the next day is just too hard. One day you'll feel okay, that you can do this and the next will feel nearly impossible to get out of bed.
You'll have to decorate your baby's grave for holidays instead of celebrating them with her. You'll always be on the lookout for items for her grave to make it look "cute".
If you decide to get pregnant again, it will be so scary. Every day will be a different day. You'll pray to God to just let her live. You will learn a whole new kind of faith. You will question if there is anyway you can love this new little bundle of joy as much as the bundle of joy you had to bury. You will question everything you did when you were pregnant the last time. Did this contribute to her death? Did this or that? Then, you'll realize that this new baby is only here because your daughter died. You'll realize that someday this new baby will realize this, too. And then you'll question how you can possibly raise her knowing that she was wanted and she is loved, and not just because her sister died. How can you raise her making sure she doesn't feel "second"... You'll have days you are over the moon excited to see her, though. You will have moments where you cry just thinking about holding life again. Holding your baby... Holding your living, breathing, crying baby... And the thought of that will make you smile because it is so good.
You'll be mad at God. Sometimes so very angry. Then, you'll realize He is still good. You will realize He has never left. Your relationship with Him will grow and you'll realize how He is in your house more than He was before. You'll realize He gets it. You'll suddenly have a whole new respect and understanding for God sending His only Son... it'll hit home to you more than it ever has before.
You'll realize your life will still be good. You'll attempt to make the best of your life everyday. You'll gain a new perspective on life.
You'll realize this is your life... that you will live with this every day. You'll have days that feel impossible and days that do feel possible. Nothing about losing your baby is easy. Absolutely nothing.