[-Pv-]

I too have complained about the times when even at max distance setting (make sure you use 24K yds - around 12 miles) the enemy fires the moment the sim starts.
In my experience, this range is not set to the closest target and forces in a group might be even closer. In the modern sensor and threat environment, 12 miles is across the street while normal uboat engagements were 1000 yds or less.

Does the game sometimes give us a "kobayashi maru"? I think it does.

"...i head out and intercept 3 subs, identify them and proceed to ready..."

"...immediatly set myself to run silent, i basically crawl..."

"would try to escape enemy destroyers yet in this game, it seems running silent litterally does nothing at all"

There is no simple answer to your dilemma.
There may be information the sim is making available to you which you are not yet taking advantage of.
Layer:
Depending on changing circumstances, you may need to work both sides of the layer. Just above or just below has certain advantages depending on where your nearest enemy is.
Signature:
As soon as you identify your nearest contacts, pay VERY CLOSE attention to the CONTACT portion of the signature tab and keep cycling through the contacts. These estimates of how DETECTABLE you are can change rapidly.
Know your enemy:
Inspect the vessel profiles on your detected enemy. If they have towed array, it's very difficult to hide from that. Work the layer if there is one. Know how to work the shadow and to know when you cannot.
Silent:
Pay attention to CONDITIONS tab. If ambient is in low 80s or less, even a quiet sub can be heard. Consider: The average room in a home with traffic passing by and no entertainment playing is around 55-60 db. A quiet jet aircraft taking off at 100 yds can be 90 - 110 db. The mod 688i model in the game self noise is 116 compared to the default Narwhal which is 105.
Five knots is not always silent enough. Launch transients are not silent. As soon as you attack, you have given yourself away. You are now in evasion mode.
In this game, your initial attack must almost always be from the maximum range at which you have confidence your weapons are pointed in the right direction and have the endurance to reach the targets.
ESCAPE and F4 keys:
If surface ships and subs were your only threat, the game would be so easy you could p[lay it in your sleep. However, the roving dipping helos and MAD equipped aircraft are even more dangerous than your vessel opponents because they are not hampered by their own self noise. You can systematically eliminate the vessel threats before or as they detect you, but you cannot reduce the air threats. All you can do is alternatively sneak and run trying to move away from their search area.
Attack planning:
You need to use the full 3D environment vertical and horizontal. As soon as you attack, you need to switch mental gears to evasion mode. Make sure you have as much water available to you for evasion and re-engagement as possible. You cannot fight and run from inside a box.
Weapons:
Take full advantage of your weapons. Your torpedo paths can help or hurt you. The MOSS can work miracles used properly as both an offensive and defensive countermeasure.
Risk:
There are times when you need to throw all caution to the wind and charge ahead full tilt boogy confusing and forcing your enemy into the defensive, then pull in your spikes as all the noise they are making covers your escape.

These are only a few of the tactics you should be considering. Most of all, I'll say what I have said before:
Play the default game default single missions using the default vessels and the Narwhal until you can beat every mission without a sweat before you change subs to build of your experience and confidence, then switch subs, then on to the campaign. Just because a particular sub is new or cool or a favorite does not mean it's the best sub for the job.
Again:
"it seems running silent litterally does nothing at all"
Yes that is true. Keep that in mind. Once the air threats find you, you are close to the enemy, active sonar is pinging you, torps, charges and rockets are in the water, silent is your enemy, not your friend.
-Pv-