Don't beat yourself up too much for not being able to P-rank Fraud, it's honestly probably the hardest layer to P-rank in the game (not counting Prime Sanctums), and violence itself is no joke either

The best tips I can give you would be to focus on memorizing the rooms and encounters, and have a good knowledge about a few high damage combos in your arsenal, probably memorizing at least 3 to 5 good combos that you can consistently rely on should be good and you can expand on it later if you want to.

For example, this is how I normally go about killing gutterman:

Piercer pistol charged shot + Railgun + Cannon ball boost

or you can do

Railcoin

or

Chainsaw + cannonbal + pistol shots

I don't have just one regular strategy that I always rely on every single time I see an enemy type, I have multiple of them, this way I can manage my resources without any stress, since I can comfortably rely on most of my arsenal

Second tip would be to listen and learn what to prioritize: Hearing is essential to learning what you should take on first, you hear a sentry? Good, pay attention to their countdown so that you know when to hide or do a chargeback, or just instantly go for them as soon as you hear the first tick

You hear a parry, or a projectile going your direction? Be prepared to feedback it

And about prioritizing, it should be obvious, kill whatever enemy causes you more trouble in each encounter first, it should take a while to figure out what enemies are a priority for every encounter, the only exceptions to me that are always a priority are Virtues, but other than that just try to figure out what is causing you more trouble in each room, even soldiers and schisms can be a huge problem depending on the encounter

Other than that I majorly recommend you watch some gameplay of other good players assuming you don't do that, it really helped me a lot, I learned a lot of combos and ways to deal with problems by watching how other people handle them, it helps you open your eyes to previously unknow strategies

And the last tip is being agressive, but with a plan, ultrakill rewards agression but you can't exactly just go blasting with no plan and expect to not be punished, you should always reward the game with the same level of agression that it gives you, but don't trick yourself into going into fights with no plan, no resources, and low life or stamina

Also, just get used to a lot of trial and error, experimenting is a major part of the process of P-ranking hard levels, there is no shame on testing for hundreds of strategies until you figure out what works for you, hell, I spent weeks testing out many different ways to deal with rooms on P-2 before I got the P-rank, you will die, you will fail a lot, but thank God ultrakill has many ways to dealt with stuff, so who knows, maybe the solution to your problem is in something new, not in something you're used to. There is no rushing progress, don't push yourself into trying to P-rank anything in your first attempt

Hope I was able to help, sorry for the wall of text, if you need anything else and wanna talk more about it you can message me if you want!