I don't have room in my mind and can't even think about others

When you're busy with new things or work, it's natural to do your best.
However, Keita is trying to “care about others,” so please be kind to someone when you feel like that one day.

Keita-sama
This is a humble answer to the question.
“Do your best for yourself,” this is usually the case for everyone, and I think it's unavoidable to think that way.
Everyone loves themselves, values themselves, and they become themselves, themselves...
In Buddhism, being obsessed with oneself is treated as “infatuation,” and as the obsession that should be exterminated the most.
However, it is also a very difficult place for us ordinary people, even if they are suddenly told to “get rid of stubbornness.”
Therefore, I recommend that you try to calm down, examine what exactly is your “self,” “yourself,” and carefully analyze it. In that case, it's a good idea to be able to advance little by little by relying on the wisdom of various Buddhist textbooks and treatises.
Eventually, no matter where you search for that “self,” you will notice that you cannot find a “self” that can be perceived as such. “I am an empty being without substance.” Of course, just being aware is not enough, and little by little, it becomes necessary to adapt that awareness to one's own mind, habits, and practice, and release various obsessions with oneself and things involving oneself.
However, don't fall into desolation or emptiness just by understanding the above. Even though you have no substance or are empty, you certainly exist.
The way it exists is “as luck.” The explanation of the three layers of “luck” here is that it is difficult due to the character limit, so in an extremely simple and easy-to-understand manner, it means that you are an entity supported now, until now, and in the future by countless “relationships.” I'm sorry for the mundane expression, but it means that they are living beings alive by various “relationships.”
I can fully understand that they are “living alive,” and I know that when a sense of gratitude, recompassion, and compassion for those countless “relationships” begins to develop at least a little bit, they will finally be able to think about others.
First, why don't you start by analyzing exactly what your “self” is, at least little by little? I pray that the light of wisdom will shine on Mr. Keita.
Gassho
　

Keita-sama
Nice to meet you. I'll give you my answer.

Everyone's self is most important.
Please first feel happy that you are doing the best you can about yourself right now.
Also, remember that behind that happiness, there is always someone else's presence somewhere.
Even if you don't know right now, that day will come someday.
At that time, be sure to thank others and be kind to them.
Gassho

Hello Keita.

You're doing your best, aren't you?
I'm busy every day because I have so many things to remember about work. People tell me to be kind to others, but I really can't even care about people.
I think I'm important.

It's like a monologue and doesn't look like a question, but I'll write what I think.
It seems like time has passed since the question was asked (this answer was 2013/02/23), so do you remember your work too?
If you're looking for results, whether at work or in personal matters, you need to cooperate with others from the root part. Of course, you also need to cooperate with yourself.

If you don't fulfill what you want and wishes while giving joy and kindness to others other than yourself... you may lose money as a result.

Keita seems to be aware that “I don't have room in my mind and can't even think of anyone else.” It's not a law of attraction... but if you are aware of your “self that you have room in your heart” and “yourself that cares about others,” your reactions from those around you may also change. Try aiming for happiness while getting help from people around you.