This is not only regarding to romantic relationship but any types of relationship in general.

I recently had a a few beers with some colleagues afterwork. We played this game call "a piece of advice" where everybody give the person that is playing 1 honest advice. 7 out of 8 people tell me that I need to love myself more. And yet I still don't understand what does it mean by that.

I am a extrovert, out going, funny and quite confident kind of person and yet people still tell me that I don't love myself enough.
I have been through a few relationship where I tend to invest more effort than the other person and often end up feeling lonely, but I just think it sort of a "once I'm in I'm in for good" kind of attitude. Friendship and relationship wise, I don't just do whatever people ask me to and quite selective when it comes to close circle of friends.

I do spend a lot of my free time to volunteer or invest in new hobbies and travel, also Iove reading too.

And yet sometimes I feel like no matter how much I tried to occupy my self I am still lonely. I do think that I have abandonment issues this due to my family circumstances as a kid.

I don't know....

Any advice ?
:)

You're asking a very big question.

Firstly, I'm not sure how close you are with your coworkers, but maybe find the closest one and see what they meant by the fact that you need to love yourself more - find out why they think that because there should have been something that you've done in the past, which lead them to think like that. Ask them for a specific example.

Secondly, it sounds like you know yourself, or at least you know how to enjoy your time. You say that you don't do whatever people ask of you, but maybe there's a discrepancy between whether you think that yourself, and whether other people think that too. Perhaps you've convinced yourself that you don't follow other people's orders, when to other people you really do. (I don't know you, so this is just a theory).

Thirdly, it depends on the definition of "love yourself". In one way, loving yourself could mean taking care of yourself well, and it sounds like you do that already with the reading, travelling, etc. But then, the majority of people can do that right? Which leads onto the second point, do you let people treat you like trash? Do you let other people use you, or play with your feelings? Do you think you are worth other people's time? Do you let other people give you their time of day?

Perhaps this is a question of whether you think you VALUE yourself enough. Based on your idea that you're always putting MORE effort than the other person - maybe that's your answer. Because you're always putting in the effort more than the other person, this leads to the other person becoming complacent. As a result, they realise that they don't need to put in any effort to maintain that relationship, because you'll always be interested in them, and therefore ends up "using" you (if that makes sense). Consequently, you're the only one powering the relationship, thinking you're forging a meaningful relationship with them when in reality you're not.

While that is the case, my advice is not "stop putting effort into relationships from now on." But more like, lessen the effort that you're putting in, so that you can give the other person a chance to "prove" that they value you. Once the person realises that you're not reciprocating anymore, they will return the favour and effort, because they've realised they are losing you.

I'm not saying that my advice will solve all your problems, but hopefully it should give you a third perspective and some food for thought on this. Loneliness cannot be solved by occupying yourself (if anything, you're just trying to mask the loneliness) but rather finding meaning in your relationships, as this fulfilment comes from within. Once you value yourself, it should be a chain reaction in that you will expect other people to value you too, and meaningful relations should stem from that.

All of this is hypothetical, but it could be some help I hope?

I came back to have a look if anyone has replied to my thread but I did not expect such a cool and long reply :D thanks for that, especially reading this during quarantine time.
Your analysis makes a lot of sense especially about how I perceived myself comparing to the other people. I seek help from a psychologist on my mental state recently because I want to make a change in my life, especially with many fail relationships with the same patterns, repeating again and again and again. And turned out I have OCD and anger problem (severe OCD with false beliefs in strange routines and mild anger problems) and this makes my thinking and behaviors different from each other. So I appear to be very friendly, successful and bla bla bla; but inside my thoughts are extremely skeptical (towards myself and others) and I tend to overthink in a relationship, hence the putting effort too much because of fear, of if I don't put too much effort something unexpected will happen.
I agree with all of your points actually which make my problem seems smaller now :) I think the therapist actually help as well, finding out about how my experiences as a kid could affect me so much during my adult hood; and in order to overcome it, I need time and stop rushing into things and quit if it does not work out and then blaming myself for it.
I did also asked my coworkers about their opinions from the game that night, 2 of them were having a smoke with me during break and they told me the reason why they said that was because I always help other coworkers to finish their tasks while also having to do mine (of course with proper reasons like they have to go get their kids or they are not feeling well), and they think that I am being too nice and try to build a good relationship with everybody and sometimes it's a bit too much (basically they told me to stop being too nice). So I just smiled and thanked them. But honestly speaking, I take the tasks because I want my team to have good results and I know those people can't deliver that so... yea. Funny how people perceived things so different right?
I hope you get to see my reply :D
And hope you are safe and healthy, especially during this virus breakout.