Seriously Discouraged

This is kind of a long post to read, but I'm really looking for some advice and/or answers to help me proceed with this game.

I'm seriously discouraged in terms of building up my overall power for my Descendants and weapons lately. I went through the main story smoothly enough but now that I'm faced with end-game content I find that I'm extremely weak against everything and just can't get the right gear to upgrade myself to a capable state.

Notable Stumps I've Run Into:

1: I've farmed for level 100 Reactors and External Components and I'm now at the point where I doubt I can get anything better for those categories. Despite that, I still don't feel like they're doing all that much more to help me.

2: I have some decent Modules and have a few upgraded to the maximum level, but most of the time I don't have enough Kuiper Shards to fully upgrade all of them. Additionally, most of my Descendants and weapons don't have the Module capacity to hold all of the Modules I want to equip even if I could upgrade all of them (Yes I know you don't have to have every Module slot occupied to be effective). Even the weapons I do have good Modules equipped to feel like they're doing "tickle damage" to end-game bosses and even some Hard Mode enemies.

3: Some builds I've seen online feature some Transcendent Modules that could really help me with finding certain play styles that might be easier/more suited for me, but the chance to earn said Modules come from completing end-game missions, missions that I'm not appropriately equipped for at all.

Ultimate Problem:

I know how to - and already have - farmed for the best level 100 Reactors and External Components I could find that favor Defense and HP. I know I can gain Kuiper Shards from dismantling spare Modules and opening vaults. I know I can increase the Module capacity of my Descendants and weapons by leveling them up and assigning a Module Socket Type to them to "Prestige" them and make the Module capacity cost for the specified Module type cheaper.

Despite all of this my stats aren't anywhere near as high as I've seen other people's stats to be. I see the things I need to do to upgrade myself further to hopefully become end-game capable, but to reach that point it seems like it would take an ungodly amount of time spent grinding.

Does becoming end-game capable really require me to dedicate my life to grinding for the gear I need? Do I really have to play missions over and over and over again just to level up and MAYBE get the necessary gear I need? Am I missing some things that could make upgrading easier?? It's discouraging because I just don't have that kind of time, or patience for that matter.

If anyone is interested in my stats... Firearm ATK: 12,144.42
Skill Power: 17,697.54
Defense: 60,023.05
Max Shield: 1,304.84
Max HP: 1,356.22
Max MP: 230.02