I’m glad to hear that your faith in Christ is being reconstructed. What you are wrestling with regarding the existence/nature of hell is quite common, seemingly more so today than in the (recent) past. It’s quite a significant topic.
As with all theological issues, the fallen nature of humankind renders our sense of justice regarding hell less reliable than God’s Word. Thus, examining what the Bible says is my strong recommendation. Let me highlight a few of the many Scriptural passages which I think are relevant here.
In Romans 1:18-32 we see that everyone has some knowledge of God through observation of the natural world (particularly poignant for scientists!). Certainly some have heard clearer expressions of the Gospel than others, but no one can claim total ignorance before God (see verse 20 in this passage). So how do we know who can be held responsible for a certain level of understanding of the Gospel, and what level of punishment is deserved by those who reject the revelation God graciously provides?
I think the short answer is: as humans, we cannot know this fully. Thankfully, we are not the ones in the position to make that decision. God, by the very nature of being the Creator, bears exclusive rights to execute final judgment.
“Judgment” is a word with heavy, negative connotation nowadays, but in the hands of God, it need not be seen that way. Consider Deuteronomy 1:17, Psalm 7:11; 9:7-8, 75:1-10, Ecclesiastes 12:14, and Matthew 25:31-46. God, being perfect, holy, righteous, and omniscient, can be completely trusted to make accurate judgments. His decisions about who is responsible for what (or to what extent, or how much, etc.) will be thoroughly and completely righteous. He will not be biased, unfair, misinformed, moody, or be afflicted by any other malady or limitation that would cloud His judgment. The same cannot be said of any human, which is why implementation of judgment only ceases to be problematic when it is put in God’s hands. Justice will indeed be served. So while it is natural to ask some form of the questions “who deserves hell?” or “how bad should hell really be?” the answers are only partially revealed to us, with the specifics left up to God Himself. Because of His perfection, God’s people don’t need to worry about what they don’t know and can’t control. In fact, they can rejoice in His judgments (see for example Revelation 18:20).
Personally, I have found that absorbing those truths more deeply have made my own questions about the nature of hell less pressing. Whatever the answers, I can trust that God, who knows better than any one of us, will do the right and righteous thing with regard to each person’s opportunities in life and how they responded (or didn’t) to Him. A place of punishment for those who reject Christ is certainly taught in the Bible (Matthew 13, Revelation 20-21, several others), though complete details about what it is like are not revealed to us at the level of our curiosity. But as I mentioned, I think such issues gradually fade in importance when we remember that the holiness and righteousness of God oversees the whole process.
Let me also add that we would all be deserving of His wrath if not for Jesus’ substitution in our place (see Romans 3:10-26). So those who are saved and do not receive His wrath have no basis for boasting over anyone else (see Ephesians 2:8-10). God is the one who gets the glory for it. Praise God for His plan of salvation!
There are entire books devoted solely to the topic of hell from both believing and unbelieving perspectives, so a comparatively short reply here will certainly not answer all your questions, but I hope you consider this a start. I pray that your journey back to faith will cause you to continue to trust and love Him more each day.