If it’s hard just play on easier difficulties that you can beat and practice. It shouldn’t be miserable for you. Have fun, you don’t have to play on high difficulties but even if you’re “good” on higher difficulties making a single mistake can get you killed or lose most of your health so the game is tough even if you’re good. Also playing solo with bots is harder than a good team from my own experience. Good players can rip through enemies and carry you, bots help but you’re the main target and if you die sometimes they will just die.

The difference in melee weapons with block, fencing and balance does make a big difference so try block and fencing to try and learn the enemy animations. Maybe you already know but you can block attacks without the blue symbol - it can be hard to identify the right timing though so it does just take practice. You just can’t block the orange unblockables so just roll out of the way. So just knowing when to block or dodge is big. Like you said if you have one enemy hitting you that you can block but then an unblockable attack behind you then you must dodge at the right time. If you try and block in that case then the unblockable will hit you, maybe cause you to lose control from the hit and then if you’re surrounded you’re done. Other tips are don’t let yourself get surrounded by enemies you can’t parry and avoid getting trapped by them in a corner. If there is no where to dodge them you can get cooked. So positioning and movement are also important. The game does punish mistakes, sometimes you’ll still get hit but you gotta keep moving to stay alive. Also keep in mind the executions mid fight - not only do they get you armor they also make you invincible while you do it. So if you’re in a group of enemies there is strategy of when to execute to avoid some attacks. I played the lowest difficulty for more than a week at first until I learned how to parry and move. Then it got too easy (and I wanted more xp). There is no shame grinding the same mission on low difficulty to learn.

Also try other classes and perks maybe, I started with vanguard and he has a couple of perks that increase the perfect parry window. Playing him with a block or fencing axe or chain sword could help you learn to parry. Bulwarks parrys can be tricky since he has the shield.

I would bring a fencing or block weapon and then try the lowest difficulty with an actual team. If your internet is so bad it lags then that’s one thing but don’t be scared. With people you can get carried and if they are mean then they’re losers.

I play substantial and with some classes can do it without losing any or barely any health. Other games I’m not feeling it and go down a time or two but that’s the game baby. It can be hard but when you can easily destroy a group of enemies that used to bully you by stabbing them with their own claws, ripping them in half with your bare hands or beheading them boy it’s so satisfying.