Frankly, “kurwa” is an incredibly versatile swear word. Depending on the person it will either be used as a severe one (I only use it when I do something that causes me physical pain, otherwise I just use English ones, as they feel less severe for some reason), but I’ve heard people who use it every second word, like I sometimes do with “fuck”. However, I can offer you alternatives for each of your hubs, ones that work with the polish language (as I understand that it’s pretty difficult to do so with languages one doesn’t know themselves).
So, for “hell”, I would just use “kurwa”. Maybe “kurwa mać” in the case of “bloody hell”. It definitely aligns with how I’ve seen people use the word, as well as used it myself. What the kurwa! does sound a little strange, but all polish swears will and this is the closest option. It might seem a little severe, so if you want a milder option, you could go with “kuźwa”, something you usually say when you’re about to say “kurwa” and then realize that your parents or incredibly religious family members are in the room (I know this from experience).
When it comes to damn, definitely use “kurwa”. You dropped something? Kurwa! Stubbed your toe? Kurwa! You get the point. Just like with hell, if you want to use “damn it”, you can use “kurwa mać”. This is the easiest one, as I don’t have to account for genders and forms (will definitely explain when I get to “fucking”).
With shit I would suggest “kurwa” again, but we actually have a great equivalent. “Gówno”. Translates literally to “shit”, used in similar situations. Will sound strange sometimes, but as I mentioned previously, all of them will. Polish have too many form for that not to happen. However, this is the best option.
Shitty has the same problem “fucking” will. Polish has forms and genders. You can use “gówniane”, which is the gender neutral form, however, in the example you provided, the proper form would be “gówniana”, since “excuse” is female in polish. Basically, either don’t use polish in this particular example or just use the gender neutral form I gave you, as I doubt you want to have to check every word to see its gender before deciding what swear word to use.
Fuck is another pretty simple one. As I told you, “kurwa” is the polish equivalent of it. Yes, because of what I mentioned before it won’t be the most severe in this language, so if you’d like to keep that escalation, you can use “kurwa mać” instead. It’s like a more severe form of “kurwa”.
Now we get to the dreaded “fucking”. Just give up with this one. You could technically use “jebać” as a literal translation, but then we look at the example you provided and it has the same problem as shitty, only worse. Just like with shitty, you’d have to use “jebana” because the word “shame” is female. But it gets worse. The word “jebać” isn’t just gender neutral like “gówniane”. It actually doesn’t count as a verb in a sentence. Yep, it’s a verb that’s not a verb. In English, you’d call that an “infinitive”. So it’s like “sit”, “eat” or “go”. Technically, you can use them in a sentence but not without fulfilling specific conditions. So yeah, don’t bother with this. It’s more trouble than it’s worth.
Sorry for the incredibly long post, but I love talking about my language. It’s one of the hardest languages in the world to learn, so I’m pretty proud to be one of the people who know and use it on a daily basis.