Now, it is time to focus on people other than yourself. Most other advice on here is awful; it amounts to different directions to run on the hedonic treadmill.
Instead, you have to give back now. What good is there to be done, that only you could do? What will be worse off if you don't lend a hand? This can range from finding better ways to support and mentor your children, to donating time to tutor students in programming, to building a well in Africa. Think hard about what you really care about, and then work hard to bring that into being.
We need meaning in live. And for a long time religion gave that. But we threw that out. We now try to get "profesional therapy help". But it hardly has any scientific backing, and no one but religion has been able (even though it fails often) been offer te give any deeper answer to the question to "whats the meaning of it all".
The best solutions people like Robbins or J. Peterson offer are: just keep running so you don't think about it.
The point of hobbies is not "getting good at them". It's enjoying them for their own sake. Otherwise they turn into ... work.
> I'm just a blip in the universe and when I'm gone it will be unchanged, the same as if I had never existed.
Yes. The Universe doesn't expect or have any special plans for you.
But hey, that is not that bad. Consider the opposite. The Whole universe having a plan for you. The whole infinite Cosmos. Just thinking about you and having a plan for you.
I don't know about you. But it would give me a panic attack.
It's ok that the Universe doesn't have a plan for you. This frees you to assign your life whatever meaning you want - and to change it at any point! You can also feel gratified about fulfilling your self-assigned potential or feel extremely disapointed if you did not. Or, change them again. Some hold that the secret to happiness is having the right expectations about oneself.
> And now what?
Therapy worked for me.