are you on the PC? If so, consider trying several of the quest mods that are up on Nexus. Be aware that even though ppl have played these fine without serious issues, all mods at this pre GECK point are still in their beta stages. So you're basically freelance beta testing if you dl and play these. Just make a copy of your existing saves before installing anything.
Also basically what many other ppl have been saying in this thread. But by your own admission, you're no new player to the fallout universe. So you already know the game is what you make of it. You're going to have to get creative and do RPing/exploration instead. At least until Beth makes mods official so you can play all the quest mods you want.
I've been doing this since the first nexus mods started coming out. I don't play to complete or "beat" the game for achievements as much as exploration. So I backed up and removed my original saves from the game folder. These saves were with the original male PC I created from day 1. Given this PCs military background, I'm RPing a good alignment, dutiful soldier/frat boy character which will ultimately join the BoS as part of the MQ. This PC will try to seek world peace as his ultimate goal in the MQ. So I'll use this PC to do the best ending working with all 3 factions.
I also wanted to explore the Commonweatlh with a more "evil" and misanthropic view of the world. But didn't want to jeopardize any progress made with this male PC using the pre-GECK mods that are currently out. So I started a whole new and heavily modded game to play a female PC. I plan on having this PC join the Institute, because this is the only faction which appeals to her high intelligence and very cerebral nature. Like her GI spouse, she believes that victory comes on the back of sacrifice for the greater good of the world--provided this ideal doesn't require her own. So basically, she has a selfish, egocentric streak which her GI spouse completely lacks. Which opens several RP interactions, conversation branches, and opportunities with NPCs which my first PC would have never explored.
This PC was already saucy/sarcastic to begin with before the fallout. But she was also a devoted mother to her husband and infant son. So after witnessing the murder of her spouse and kidnapping of her child, she became a changed woman. She became extremely cynical and vengeful after discovering what was left of the world after leaving the vault. And with this discovery, also developed something of a mean streak. Unlike her dead spouse, she's a loner and so prefers solace in her travels. But will suffer the companionship of Cait or Nick who are somewhat misanthropic like she is.
Also being physically less imposing as her vet hubby, I made her a high sneak, high charisma and intelligence character build. I use these main attributes in her personal quest to hunt the ones who wronged her family. And ultimately to find her beloved son.
In the 80 hrs it took you to "complete" FO4, did you truly complete the game as both genders and explored the endgame for all the involved factions? because if so--and you're not motivated towards d/l any existing Nexus mods, or do any sandbox role playing--then you're stuck in limbo until either GECK or the first DLC comes out.....