I really can't rec Winter Wolves enough-even if, for some reason, you can't follow them, they're a very good gateway to other indie dev studios. Just by going on their twitter page has twitter recommending me other indie devs to follow. Which leads to more once you follow those devs, and so on and so forth.
Crescent made a good point on the 1 dollar tiers, just want to point it out to you as I'm not sure how itch.io threading notifications work. Don't want you to miss it.
As to feeling uncomfortable/irrational about asking for more expensive tiers, don't feel bad about it. That just means you have a strong moral center. Business is...fraught with ethical questions to say the least. Stores put milk in the back so the customer walks past all their other products and gets tempted. Is that wrong? You'll get many different opinions on that. But like. You're just trying to make a living, not get super rich, so. Honestly, just value yourself and your work. You make excellent games, you put a lot of hard work into them. The relationship you have with backers is much more equal than you think it to be.
Here's some kickstarters I thought you'd might want to take inspiration from. Some have delivered, and others not, but either way, how they set-up their kickstarter got their project funded. I'll note which ones have delivered and which haven't, as that may factor in which you choose to look at.
https://www.kickstarter.com/projects/argentgames/red-embrace-hollywooda-vampire-visual-novel/description - a pretty recently done kickstarter, they have delivered. Notable in that a lot of their tiers seem to be digital focused.
https://www.kickstarter.com/projects/896740058/wishes-in-pen-chrysanthemums-in-august-otome-visua/description - I believe this was run sometime last year, haven't delivered yet. You can take inspiration from the tiers, but honestly I think their whole "About Campaign" section is what really shines.
https://www.kickstarter.com/projects/2046671315/dead-wishes-a-visual-novel/description - Delivered. I find the "designing/adding to a background" to be a noticeable digital reward.
https://www.kickstarter.com/projects/steamberrystudio/changeling-gxb-mystery-romance-visual-novel/description - Delivered. Most of the tier rewards are digital based.
https://www.kickstarter.com/projects/traumendesmadchen/chronotopia-a-dark-fairytale-visual-novel/description - Not delivered, but pretty close to completion. Overall kickstarter and tiers are good to look at for inspiration, overall.
https://www.kickstarter.com/projects/490618601/queens-crown/description - Ahahaha damn this one hurts to post but. Anyway, likely never getting delivered, but regardless I still think the kickstarter overall is pretty good inspiration,
https://www.kickstarter.com/projects/329540171/seven-kingdoms-the-princess-problem/description - Very close to completion. Of interest to you is the tiers, a lot of which promises character scenes as rewards.
Lastly...don't overwhelmed! There's a lot here I linked you to but you don't have to follow to the letter. The above kickstarters are just suggestions for what you want to do and offer. I will keep trying to help so long as you keep wanting it. Best of luck to you!