Again, it’s most likely very fixable but you have to WANT to fix it.
I have just under 50 toons. The majority under lvl50 and of various ATs, with only SOs (in other words, not much influence invested) and none are experiencing what you are claiming.
The only one that comes even remotely close, is Dark Armor - and I can still make it through a mob.
If you want help understanding builds, we are all here to help.
These forums are full of people asking for help with various issues - from newbies to veterans. There’s nothing wrong with seeking a little advice.
But if you just want the game made even easier than it already is, rather than trying putting in even the tiniest bit of effort…..well, I’m really not sure what to tell you.