I know how you feel about achievements and numbers. I used to have that, but managed to put it under control.
May I know what makes you feel like you need to get achievements and numbers, do competitive play? For me personally achievements are just a way of having some goals and things to do after I finish the game. Like I'd never play the game just for achievements, but just knowing that I can always go back to the game and try to get all achievements or play on harder difficulties makes it feel like there's another adventure ahead.
And as of competitive play - I personally like to play a few fighting games, so I know that they always try to make you interested in online play, getting higher rank and etc., but I'd say I can control it and just play for fun. For example, if I don't feel like playing anything "heavy" or new, I'd just go and fight a few matches in SoulCalibur VI or Street Fighter V, try to learn a new move or tactic and it sort of refreshes my feelings. Then I close the game and go for the "heavy" ones. Maybe you just need to find some way of these competitive games making you feel better without being focused on the numbers? Let me know if I can help.
As of your final sentences and transition from adolescence to adulthood, I think someone made you feel bad about your hobby and it's difficult for you to accept games unless they're on handheld because of that. Or you can't make peace with the fact that it's not wrong to have entertainment as your main hobby and devote yourself to it.
When I was growing up, my grandparents would always try to make me think that work is the most important thing in life. But it's not - your hobbies and you are what matters the most. Work is just something we have to do in order to be able to enjoy and support ourselves. It's important to find work that doesn't make you feel bad and it's great if you like working, but I think it's wrong to focus solely on work because that just takes away your personal time, like some people who get so into it that they don't know what to do when there is no work. They come home and feel scared because they don't know anything about themselves: what movies they like, what food they prefer etc. and instead of exploring themselves, they'd just try to think about work.
Games have some work into them, too. You can't have fun in a game without doing anything and it all requires some effort which may or may not always be that great. Like I'm currently playing Kingdom Hearts Re:coded - it gets a bit repetitive when I have to fight the same enemies over and over, or struggle with bosses but it is fun. Now if I had to do the same thing in a game I don't like... that would just be awful. So, I think you just need to explore your taste a little more, find something that makes you feel great even when it's not super-exciting and then you'll feel better.
Finally, you mentioned meaning to life. There really isn't much meaning to anything: we work to get money, we make families because humans feel bad alone and we raise children because that's our responsibility. We're not meant to do any of this, but we do it because we want to. I remember reading those history books and some literature... usually the ones who would try to place this burden of "meaning" on us were some propagandists or self-centered kings/presidents who just wanted to control people. Sometimes there are things we need to do, but it depends.
So, what I mean to say is that it's perfectly okay to spend a lot of time on games, think about them or even try to get competitive and all that. As long as you know it makes you feel good and it's not causing any great damage to society or people you love. I always use the example of thrown out batteries - if you throw out batteries without recycling them, would anyone get hurt? Technically, no but eventually those batteries will start causing ecological damage and everyone will get hurt. That's the same with being immoral or focusing too much on work - nobody gets hurt, technically but eventually everyone gets hurt.
Playing games and being excited about them, maybe even obsessed is fine as long as you have it under control and can prioritize taking care of your loved ones or working just enough (!) to have the money you need for yourself / your family. If games are something that makes you really happy, if you feel excited about seeing all of those worlds and stories - then there is absolutely nothing wrong with loving them.
I used to think that I know all about games and the ones I played were kind of... eh, they just weren't for me. They were good games but not something that I like a lot. Eventually I tried to be more open-minded and found out what I like. Maybe it's the same for you with competitive ones? I'd be glad to help you to figure out what exactly is your preference.
