New and ranked up to quickly

Yep, it's common for killers to rank up too quickly, then have difficulty getting back down to the rank they feel they should be at.

It's because there's a sudden leap in player skill around the purple/red ranks, which changes the game from being killer sided, to survivor sided.

You won't do well in red ranks unless you play a strong killer (Trapper isn't one of them) and take a lot of gen defence perks (which you don't have there).

I am generalising of course, but statistically speaking, you'll be facing better survivors at that rank who know how to play with killers.

The perks you have on are widely regarded as 'crutch perks'. Bitter Murmur aids you when you fail (a gen pops), NOED is a back up for when you really fail (all gens are done), Agitation shouldn't be necessary most of the time, and Deer Stalker is for when you lose a downed survivor which also shouldn't really happen. They all scream "I am having trouble" so yeah, you definitely shouldn't be at rank 5 yet.

If you're happy losing a lot of games, just power through and take it as an opportunity to learn and get better. Otherwise you can try to de-rank. Your best strategy to win games at that level is to try to use the basement as much as possible, but if you want to translate over to other killers then you can't rely on the basement all the time.

Honestly with trapper you don't really play him as regular killer, you have to lockdown areas with your trap. You don't go looking for people, you have to wait for people to come to your area. But I get what you mean, in red ranks survivors are usually a lot smarter and will loop you infinitely, and disarm any traps you put.

I tend to place traps in areas were I know survivors will jump over, and or walk around, or while in chases. I usually place my traps to create a three gen set up. so around a certain area. As the match tends to go on, I will place traps on generators or choke points in certain maps such stairs and thing like that. Not to trap survivors but to alert me know if they disarm my traps. So I can go. But mind you if it's vs a SWF my way of playing may not work.

Something nobody else has said so far:

Once you start going against better survivors you want to place traps in the grass around loops/windows instead of directly under a pallet.

Trapper is widely regarded as one of the worst killers partially because he spends a lot of time setting traps which may or may not pay out. This is why you want to hide traps so survivors won't just run past them and take a hit instead of going down instantly or disarm them (one survivor disarming a trap is a big net loss of your time because 1 second for them is like 4 seconds for you).

If you have to you can even place traps around large buildings survivors run you around to get to real loops. Potentially being unpredictable is one of the only things Trapper has going.

There's already been a lot of great advice thus far, and if I may, add a bit myself. Not entirely perks or loadouts, but something that helped me immensely with Trapper, a killer that used to be my hands-down least favorite, and is now my go-to killer.

As survivors get better at higher ranks, you'll definitely have matches where you'll feel the pressure that you need to immediately chase them down as soon as you can move. My advise is don't be afraid to take a little time and set up, even go a little out of the way to pick a trap up or set it up somewhere (might even find a survivor while doing so!). Even if a gen pops while doing so, don't panic, these traps may very well be the difference in catching a survivor later on (can speak from experience both as killer and survivor on that one lol). The bag add-ons definitely help you get more used to this, and after a while you may be comfortable running a loadout without them as well!

If you have time to watch some streamer, I'd recommend you TheEntitysLeftHand

If you don't want to depip and keep trying to climb with Trapper the build I use is Brutal Strength, Pop, Save The Best For Last, and BBQ. It allows you to get back into the chases faster after pallet breaks or getting enough STBFL stacks which cover Trapper's biggest weakness.

If you want to depip and don't mind losing a lot lot lot of games in a row I recommend picking up and learning Nurse or Trickster.

Trapper really isn't my main, so I don't feel it's my place to offer advice on him. If you are looking for good advice on playing Trapper, I can't think of many people who play him better than Not Otzdarva on YT. I'm also personally fond of Theentitylefthand on twitch - but some people find his roleplay to be a bit off-putting (he has a very friendly community though)

As for common tricks that most killers can learn - probably the thing that will help you the most is learning how to hide your red stain when rounding corners. (red stain is a light that projects in front of you that survivors can see, but you can't see) That red stain can be seen by survivors before you come into view as you approach corners, so learn how to hide it by looking away from corners and other edges your approaching and you'll throw many mediocre survivors off their game a bit by giving them a little less time to respond to your appearance.