*WARNING: tough truths ahead*
You've got one life, so what would be the sense in living it in a way that doesn't make you happy?
You've got to follow a path in life that lights you up. You've got to be brave and respectful enough (of yourself and others) to leave situations that no longer serve you, whether that be a relationship, a job, a friendship, a country...
But in changing your course and doing what's right for you, you must also acknowledge that it will potentially leave someone/thing else in a negative or traumatic position.
You simply cannot live without having an impact on other humans, not really. Whether that's a family member or friend, teacher, employer, your bus driver! You rely on the people surrounding you to keep your world turning and so to negate how your choices make them feel is not only negative and immature, but likely to come back and bite you later in life.
Maybe you've left a relationship after years together; something you once thought would be your 'end goal'. You feel you've outgrown it, your partner no longer fills you with joy and you know for the sake of you both, you've gotta leave. No doubt, if you're feeling that way, you should leave. But you cannot do so without acknowledging the hurt, pain and potential trauma that it's going to cause (for them and yourself!) And unfortunately, that's just part and parcel of making such a choice.
You need to, in some capacity, take responsibility for what you're leaving behind, and what that could cause, both physically and mentally. Although it's the right thing for you, it may not feel like that for everyone involved straight away.
Perhaps you've left a job, or decided to move out of your friends' place. You've thought about it and it's right for you. But you can't deny that you leaving will mean an empty bedroom to fill, or a stressful interim period until your replacement is hired. Yes, it's life and yes, it will all be okay. But know that you can't be negative or mad towards the others involved because they're simply reacting to the situation you've left behind.
Doing what lights you up is necessary to a happy and fulfilled life, there's no denying it. It's really important that you don't let the fear of disappointing others mean you deny yourself joy BUT do be big enough to accept following your heart may hurt others.
Be compassionate, empathetic and gracious in these times. Some people will need more time to adjust than you did. Allow them to feel whatever comes up for them, express what they must and carry on your merry *new* way.