Idea of 'free will is an illusion' giving me an existential crisis?

Hi, Recently been on school holidays so have had a lot of time to think and I'm going back to school in a few days. Recently been thinking too much and run into the idea that 'free will is an illusion'. Now, after a hell of a lot more thinking I'm starting to get over the idea that we 'don't have control of our actions' because of course, we are our brains so we are making the decisions, even if we had some sort of free will that defied physics and relied on some sort of soul separate from our body (which may or may not be true) the decision would probably be the same as it would likely still make decisions based on our preferences (e.g. my 'soul's free will' wouldn't choose vanilla ice cream over chocolate, because I like chocolate, if that sort of thing existed life would be chaos)

When I say 'free will' I am talking about the idea that if you rewound time, you would be able to make a different decision, all conditions being the same.

The main bit I am struggling with, which is making me have a bit of an existential crisis is the idea of emotions such as guilt, gratitude and pride, and just general responsibility for our actions.

Firstly, guilt. Why should I feel guilty of anything if it was pre-determined? I guess you could say that it is just a way of thinking: if I was able to make this decision again with my newfound knowledge, I would definitely have chosen the other option and it sucks things turned out this way'?

Gratitude. If someone has done something nice to me, say, given me a slice of cake, why would I thank them for 'making the decision to do this' when they were pre-determined to do it? You could say that doing this shows you have acknowledged their kindness so it was worth the effort to do it and they should feel good, but 'thanking someone' still has an element of being grateful that they consciously made an effort to do something, doesn't it?

Pride. How can I be proud of my accomplishments when the outcomes were pre-determined? Sure, my brain (or I) made a choice to work hard to achieve a goal, but that was pre-determined; I couldn't have done otherwise.

Responsibility. A lot of people get angry at someone for some bad thing that person have done, why is that when it is likely a result of their upbringing to do this bad thing?

It seems to plainly obvious that 'free will' in the sense I mentioned earlier (soul etc.) is impossible. Why does our society seem to base itself around this -probably- false assumption that it exists? I can't help but believe in the ideas of compatibilism and determinism (they seem somewhat the same, seeing the way that compatibilists define free will, but I'm not well read so if I'm wrong please correct me). It's making me feel completely detached from reality and incredibly stressed, I feel like I'm in some weird dream world and should break out of it. I tend to get incredibly obsessive about small issues in my life and repeatedly research ways of fixing them even when I know I can't do anything about them and should just get on with life, however this whole 'revelation' makes me feel like I've opened a door I cannot close and I won't be able to get over it. I can't exactly express how crap this whole thing has made me feel because I've sort of distracted myself from the problem by typing this wall of text strangely. But previously I was having some very dark thoughts. I don't know if I should be posting this sort of thing in a place like r/depression but talking to my dad isn't really helping me work this out, he just says 'ignore it, play life's game/get on with life' yet I feel inclined to work this stuff out or I will feel like I am living a lie for the rest of my life.

Finally, I haven't read a single book on philosophy or anything like that, I'm just a normal guy trying to get over an existential crisis after reading too much into things. So if some of my ideas are wrong then that is probably why. And any answers to these questions that involve the words 'we did it because we were determined to' are probably true but not going to be useful :P