It depends on where the high is coming from, whether we are just attaching to the feeling of being high and spacey, but if we are feeling joyful, that is okay. It is okay to feel joyful and happiness of the good qualities of others, and to have a deep contentment and appreciation of oneself. Sometimes it is harder to feel a deep appreciation of oneself, but perhaps it may be a more mature thing than just feeling spacey and high. You could try another approach to Sympathetic Joy to see whether you are really attached to the resistance of feeling joy with yourself. Perhaps ask yourself if you met someone else who had done similar actions to you, whether you can feel joy with them?
Sometimes we need to step away from ourselves, we are too close. With others, we need to step a bit closer. For ourselves, we often feel separated from others and this prevents both Compassion and Sympathetic Joy arising within ourselves. One of the techniques that we can do to feel more compassion for ourselves is to imagine ourselves as an angel looking down and feeling with the Dukkha that we are experiencing. In the same way you could do this with Sympathetic Joy. Imagine an angel, that likes doing beneficial things, is looking down and sees you as someone trying so hard to develop themselves and reflect on whether the angel, or Deva in Buddhism, would feel happy with you.
But whatever level of joy we can feel with ourselves is useful. We are not after a particular feeling, a particular joy, whatever joy we feel is good. Just as sometimes people judge their Compassion on a particular feeling they get, we are not judging our capacity to appreciate ourselves just on a particular feeling we get. There are going to be different feelings arising.
In Compassion, we have different feelings, depending on the situation. The example I often give is a little 6 year old on a bicycle and they fall off, would you feel Compassion for that kid? Normally people would and encourage the child to get back on the bicycle. Suppose you are in a car on a journey out in the country and you go around a bend to find a little 6 year old in the middle of nowhere. You stop the car and the kid is crying. You try to comfort the kid but they won't be comforted. They point to the other side of the road. You go there and down a big gully is a wrecked car. You race down to the car and there is a dead woman in it, and it is the child's mother.
Would you feel compassion for that child? Would it be more of a gut feeling? Would it be strong? It wouldn't be the same feeling as the other situation, because there are different faces of Compassion, different feelings of Compassion, different responses.
Another example I give is: suppose you have gone away from home for a few years and you come back from traveling. You look up an old friend to say, "Let's go out for dinner." But you didn't know that while you were away the friend had developed a drinking problem. You are having a nice time and your friend is just drinking and drinking. Then they start to abuse the people at the other table and quickly you say, "Let's get out of here", through Compassion for your friend, through Compassion for the others, also. But it would be much more dynamic feeling of Compassion, it wouldn't be the same as the soft, deep feeling of Compassion for the little kid who just lost their mother.
So Compassion has different faces, joy has different faces. When we see someone doing really something wonderful, we have an uplifting feeling. Other times people are doing things not so spectacular, but continuously and we may have a different type of Sympathetic Joy. With ourselves, we will have a different Sympathetic Joy feeling. So whatever feeling or joy we can feel is good. If we feel there is a lot of resistance to feeling joy with ourselves then we may need to approach it in different ways. Different feelings arise in the practice, so try not to judge whether one feeling is different to the other. Actually, if we felt intense Compassion all of the time similar to the little kid who lost his mother, we would probably wear ourselves out and the same goes with other feelings that arise from the other unselfish emotions.