I was told by a more experienced empath that when we use our own energy to uplift others then we can feel drained. It sounds like that's what you've been doing. How to fix that and still be there for others, is to connect to source energy and use THAT to help them instead of our own. There's a lot of different ways to do this. How I do it is through meditation. I will visualize a trunk coming down from my root chakra and reaching down into the earth where it meets with a big ball of light that is source energy. Then when people are unloading their negativity on to me, I will let the energy flow through my trunk and into source energy where it is transformed and released as love and positivity. Then that love and positivity can surround them and comfort them.
What will work for each individual is different. That is what works for me. But if you're having problems with feeling drained I invite you to look into connecting to sourse energy and using that because it's unlimited.
Also, as empaths we have to be very careful that we aren't using our energy or source energy to manipulate. Sometimes it's hard for us to know where the line between manipulation and helping lies. And every empath will have a different opinion on what's ok and what's morally wrong. I don't think there is anything wrong with sending love to a person who is hurting. But I think when we manipulate a persons emotions to make them feel better, without letting them work through the issue making them feel bad, then we take away that opportunity for them to learn how to help themselves and deal with their emotions.
I hope this helps and doesn't just confuse you more.