Because your on the BB and close the action KQo is also an ok hand to call with. Still 3 betting is also fine.

Would not expect KTs to be in his calling range be aware that hes a tight opener and prob also a tight 3 bet caller (although not many hands) so KTs would not fit that modus operandi.

Still firing two barrels is ok as you pick up a lot of equity on the turn.

Preflop:

KQo standard call BBvsCO 3x. 3bet fine as well with some freq.
KQs is always a 3bet BBvsCO.
Your 3B size OOP is way too small. 4x should be minimum, 5x is fine as well.
With your super small size, the range from villain that I posted will probably be too tight.

Postflop:
Don't make assumptions about villains range unless you have minimum a few hundred hands, more like 1k+. If you arent sure, just go with usual preflop ranges.
Your range assumptions are, without reads that is, way too tight.
It should look more like this: http://www.pokerhandrange.com/hand/5wnswui4p0waqodrchcbb8zdkr1hes5rw

Vs unknown villains on low stakes, you can always add frequencies of even more holdings, because we play vs an unknown after all.
Blocking Kings isnt relevant at all, because he 4bets Kings pre.

Your analysis starts with looking at your holding and comparing it to the board.
You should more look at your entire range.
Again, your preflop ranges seem to be way off, but your range doesn't really connect with the board at all. SBvsBTN for example is a whole different spot on the same board texture, because we 3bet a number of low cards, which we tend to call here BBvsCO vs a 3x.
So the real only value we have here are our Overpair combinations.

You don't say anything about why you chose this bet size, or what your overall gameplan looks like on this board.
How much do you want to cbet? Which size could be good and why?
If we have a size and a cbet frequency, what hands could be in there?
If you dont have a concept about your gameplan in mind, you can never navigate turns and rivers profitably, because you dont know your range at all.

You say you double barrel to make him fold his pocket pairs.
Lets examine that part of his range:
22 with 1 diamond might call flop, but I agree vs this size, prob folding.
33 has a gutshot, wont fold flop and most turns as well.
44 makes a set.
55, has an open ender, wont fold flop or turn.
66 makes a set.
77 makes a set.
88 is an overpair.
99 is an overpair.
TT is an overpair.
JJ is an overpair.

As other floats vs this size, we have a ton of flushdraws and a small number of offsuit Overcards with 1 diamond.
And then a number of two pairs and sets as well, that definitely won't always raise IP when you bet that large on a flop.
Turn:
All of these will never fold on a flush turn. If you bet this large on the flop, you fold out almost all hands without a diamond. And the ones without a diamond, are still very strong hands on the 2d turn.
Look at how you justify your play: "With that sizing i showed him, that i am committed now and ready to push on river. " That is no strategical argument at all.

I am not sure where your preflop ranges come from, but I would for sure start there to improve.

Your though process about preflop is opposite, KQs is more of a 3bet than KQo, offsuit combo mostly calls and suited one mostly 3bets, because of equity and playability. Given you're 150bb deep 3bet is even worse, you want to 3bet more hands who can make nuts, plus your hand is very often will be dominated when more money will go in, so it makes it even worse. Your 3bet sizing is pretty bad, that's too small, witch makes your statement incorrect, about his range being 55+.
Flop:
You have to be extra cautious after 3betting small and SPR being so high when u have a big nuts disadvantage, so you can't cbet too often w random overcards (High SPR+ nuts/EV disadvantage= a lot of checks) , but given that you have K-high BDFD cbet is fine, but It's not a pure bet.
Turn:
Once again you have to be careful w your range, you can't blast any Flush blocker, even this combo I don't think that are pure betting, it still has decent EV to check. I'm not fan of huge sizing, on flush completing turns you should mostly blockbet or check, not having a block sizing here will lose decent amount of EV I think.
River:
I like giving up and probably mostly bluff Ad blockers as it probably blocks most flushes, given the preflop 3bet sizing and being 150bb deep.

This is a horrid board for you and your range. I like the range that Voodoo32 posted. It is a good representation of pools calling range in this spot. Could even be a touch wider.

This is a clear cbet with the KdQx and KxQd portion of your KQo range. I would strongly consider checking the other combos. While I agree with the action of the cbet, I disagree with the sizing choice. I would size it down substantially and not exceed like 33% (could even be smaller). He likely has all sets, where you will have none. He likely has 3 combos of 2 pair while you have none. I expect his nutted region to have you crushed (again, this is a horrible texture for your range). You will, however have an overpair advantage here. This is one of those spots where equities will run fairly symmetrical but OOP will have a distinct EV advantage (again, because of texture).

You don't want to 3-bet KQo in the BB vs CO. Also, your 3b sizing in this situation should be larger (12+bb).

LLL connected and monotone/two toned textures are going to be the worst flops for this situation, so I'd opt for a x/f right off the bat on the flop. L = low (characterized by being 8 or lower).