Embrace it

I play a human cleric in a party full of characters with darkvision. Granted, we don't find ourselves in pitch darkness all that often, but it happens enough.

Rather than find a way to level the playing field, I find that embracing this difference makes for some interesting narration and adventuring.

Roleplaying

I have to trust at least one other character enough to have them lead me through darker areas. The DM can get creative about how this works, without being adversarial. For example, they might say, "those with darkvision see some slippery ground up ahead." But if whoever is leading me forgets to explicitly relay this information to me, it's DEX saving throw time.

This is actually a plot point: there is one character in the group I've known for longer, and so I trust them more, and usually have them lead me. This is just one more little detail that adds to the reality of our world.

It's important to note that this is something we'd discussed ahead of time — don't just spring this on your players. Even though I, as a player, hear the DM say something, I am perfectly happy to go along with my character not knowing it. Your monk might find it silly, and not like the idea.

Establish, through a couple of examples, what might be reasonable in such a situation. Maybe they don't want to constantly be saying "I tell the monk about that thing you just said. I tell the monk about that thing too. I tell the monk about this other thing." You might all agree that unless there's a reason to be quiet (eg. stealth situations) it's said by default.

Sometimes it's an advantage! My cleric will often try to use other senses eg. explicitly telling the DM "I listen carefully for sounds of activity above," or "I inhale slowly through my nose, trying to smell anything other than the dankness of the cave." On more than one occasion it's led to sensing something no-one else did, because they were all looking for something. Again, this was a detail the DM thought about in advance. You should think about your settings, and identify things that the characters could sense, but would miss without specific attention.

Combat

Combat is tricky but not impossible with appropriate tactics. Encourage your players to think about this in advance. Many of my cleric spells have "a creature you can see" as a valid target, but not all, so I have to plan what I might do if I can't see anything. Maybe the monk has abilities that will work blind.

Being a cleric, I can use the light cantrip on my own mace or shield; maybe your party has someone who can do that too. If they do this, describe the combat to your players! Think about how bizarre this would be — a glowing mace or quarterstaff flashing around, flying from creature to creature! Shadows of goblins and kobolds dancing large and small on the walls! You've really got some opportunities for creativity here.

Mundane doesn't have to be boring

Torches are mundane, but you've still got to remember to buy them. And if it's been a long time since the last town, your monk may have to decide whether this is the time to use their last one.

Many solutions may have a price: will the whole party want to risk breaking cover just to accommodate the monk? Again? (Don't foster PvP sentiment just for cheap conflict, but this can still be interesting).

It's already a given that your party comprises characters of different classes with different abilities in combat, and during roleplaying. Sometimes this can cause issues and make a single player feel a bit useless, it's true. Completely levelling one of the senses to get around this might smooth over exploration and combat, making things more fun; OR it might close off a bunch of opportunities for the party to work together, strategise and build the reality of their world.

You need to read the book

Your original post shows that you're new to the game (which is fine), but your issues with your class are due mostly to you not understanding the class's purpose and progression. Reading the section about monks in the PHB (it's only a few pages), will answer many of your questions and should give you an idea of what to expect.

Specifically...

• Your unarmed damage will not be a d4 forever (it goes up in single-die increments (d4->d6->d8->etc) depending on your monk level, and it eventually becomes magical damage).
• You do much less damage per attack, but you do more attacks overall (look up your flurry of blows ability that you can spend your Ki points on)
• Overall, Monks just don't do that much damage, but they aren't really supposed to.

I think the last point is the biggest thing you're missing here. A monk is never going to be a damage machine. They're just not designed to do it, and if you try to be a damage dealer you'll just be disappointed.

Monks are designed for mobility, and to charge in, attack, and then charge out. This can disrupt the enemy tactics, can allow you to go after the squishy casters, can allow you to complete objectives in combat (if you're fighting the bandit leader because you want to steal the Scepter of Plotitude, a monk could steal the scepter and then run away in the middle of combat), and can setup your teammmates to do fun and interesting things. One of the most powerful abilities you get is the Stunning Strike, which allows you to stun an enemy on a hit. A stunned enemy is basically a sitting duck for the rest of party, so you can swoop in, stun the big bad, and swoop out unharmed, while your other characters can then lay out massive amounts of damage.

Now, if you're reading the above paragraph and think 'so I do the work and everyone else gets all the fun of dealing damage? That sounds boring...' then I cannot stress enough that you should stop playing a monk immediately. A monk (especially an open-palm monk) is never going to be a hero compared to the rest of your party. You will very rarely get to do anything that will make you think 'I am a superhero' either in combat or out. The monk is all about helping other people do cool things, not doing cool things yourself. If that doesn't sound interesting to you, then you're in for a very unfun campaign if you stay a monk.