This feeling, this thought has done nothing but chase me down. Today it got as bad as ever. I felt like I was alone. Like even if I went to Hell I wouldn't care.
One of the first things I thought about with this part of your post was a verse in Psalm 139 (verse 8): "If I ascend into heaven, You are there; If I make my bed in hell, behold, You are there."
I'm lifting you up. I do want to encourage you to think on the things in this thread, and in
your other prayer request thread (here). The fact that you're even concerned about it sounds like you haven't lost your faith. Satan's trying to put frustration and confusion into your mind. These confusions are not of God; the Bible tells us that God is not the author of confusion but of peace (1 Corinthians 14:33), and that the thoughts and persuations that would try to throw us off track don't come from Him who has called us (Galatians 5:8).
I've gone through this kind of stuff myself, and sometimes I still battle it. Satan knows where we're weak. He's a sneaky son of a gun; he knows he can't get some of us by coming directly to us and saying God isn't real, or that Jesus didn't die for us. So instead, he'll try to torment us in our minds, make us doubt the love that God has for us, make us feel like we've sinned too much to be forgiven. But Satan is a liar. Jesus came to destroy the works of the devil and to release us from fear. And because we're in Christ, we're sons and daughters of God. He has seated us in the heavenly realms in Christ Jesus (Ephesians 2:6). Sometimes we have to consciously choose to ignore the devil's lies, and even then we may still not feel like we're in the heavenly realms with Christ. But it's not about how we feel; it's about the truth of God's Word and what Jesus did. And we should base our beliefs on that, not on our feelings.
Hopefully this is of some encouragement. I'm praying for you, my sister. And if you need to PM someone who's been there (and still sometimes battles it), please feel free to PM me.