You are not alone.

I am so overwhelmed, that I was seriously considering dumping the game.

I felt the same at first. Keep playing, it gets easier.

It is not accurate to conflate those who demanded more content and those who find the added content overwhelming.  Nor is it fair.  They are two separate groups of people using the same forum.  Acting as if you weren't entirely aware of this conflation is either disingenuous or a confession of being uninformed about gamers and forums.  I am not sure which of those you intended to represent.

@op

You could also describe how you have been playing (e.g. what you put as your priorities in the early game) and if you just want a nudge in the right direction or a full on guide. Usually there is someone happy to help here.

Maybe I didn't play much of the base game GalCiv3 because I didn't really like it but this new upgrade to Crusade has just made the game soooo much better that I am now playing it over all my other 4x games. Honestly there doesn't seem to be much I would consider overwhelming. Citizens are straight forward, the tech tree like all these games just happens to get easier with playing the game and finding what works... diplomacy/spies are no big deal  and all that is really needed by a new player or an experienced player is just to play, make mistakes, search for things you don't understand or ask on forums and gradually the game is very playable and easy like all 4x games once you have played them through a bit. 

All 4x games especially if you haven't played this genre can be overwhelming to begin with. My advice play, make mistakes, restart if necessary and the game will become easier.

Nonsense.

I jumped straight into Crusade after a year break from GC3. The change can be overwhelming but believe me, it's all for the better. 

Here are a few basic Crusade tips:

1. Adjacency/tile bonuses are now far more important, especially on buildings that give +integer increases instead of +%.

2. Population is no longer king. Early on, higher population requires a large morale tile investment for a small benefit. Often not worth it until much later in the tech tree. Cities do provide nice adjacency bonuses, though.

3. Resources are king. Get them and get them fast. As many as you can. Asteroid mines are now the best way to get base production on a planet.

5. Invading planets is now a lot less painful and time-consuming but the AI is smarter too.

6. Leader citizens are great for wide empires while focused citizens are better for tall. I specialize in the early game too.

Huh, I've found Crusade to be a bit easier than stock GC3 was. I think it mostly just comes down to whether to do the 'land grab' correctly at the beginning. If you do, it's a relatively easy game. 

I think people complained about AI land grab so it was sort of toned down, but that just makes it easier for the player to get a bigger slice of the pie. What I would prefer is a reason not to WANT to just go out and grab as many planets and mines as possible. The Admin points and Star Citizens seem to be the attempt at a throttle but it's not even close.  In GC3, population was a huge chunk of your raw production, so gutting your homeworld to over-colonize could leave you pretty weak for a while. In Crusade, population is much less meaningful in the early game so dropping your homeworld to a far lower pop doesn't really impact your econ all that much (certainly not enough to justify not taking every nearby planet ASAP).

As I said before, I think effective military action needs to be available much earlier. There needs to be a severe price to pay for over-extending and currently there just isn't much to discourage it.