Sirius was not named after-

I am having a hard time determining whether you were being serious about that.

Anyway, you are not quite done being overwhelmed yet. Explore a touch more in the direction of your Galaxy's Rim - you should shortly find one or two of your Fallen Empires, and that will be a treat.

Also, you have an important choice to make now - Rush or Growth, and I am not talking about your military efforts. With every additional colony you make and with every pop above 10 (across your entire empire), Research becomes more difficult to complete in a timely fashion. In order to not be left behind in the stardust, you are going to want to pursue a specialized tactic or else find a balance that will let you keep pace with your neighbors.

If you decide to rush, completely forget about colonizing more planets (maybe one more if it has more than 20 tiles on it) - grind up Political Influence and start placing Frontier Outposts in resource rich areas to handle your needs there. It might interest you to know, you could potentially use such an outpost to Culture Bomb the League and steal Alpha Centauri back from them, assuming it is close enough to their border. I digress though - you can try a Rush tactic by building tall on the spot and using frontier outposts, then build your few colonies tall with research facilities. This will hit you pretty hard later in the game production-wise when you have to start competing with the industries of the blase AI, but you'll have a pretty hefty tech advantage from the get-go.

If you go for a growth approach - drop everything you are doing and start colonizing like crazy. Not every habitable planet you find though - only shoot for planets with 16 tiles or more, anything else is too much of a waste considering the Research penalty. Then invest in the infrastructure of your planets and try to go for a research-oriented ecology on each. This will leave you sucking wind until the midgame, but once everything is built up you'll probably be the dominant scientific power in the galaxy thanks in part to your Fanatic Materialist ethos. The eventual goal of this approach is to overpower the Research penalty by adding more science per planet than average.