As a general rule, you should look for self-sustaining virtuous systems in your life. That’s a fancy way of saying that you should look for relationships, whether with people or activities, that give you back what you put in.
One way of looking at this is the way my father often looked at hobbies. Whenever he had a hobby, he liked to find a way to make just a little bit of money off of it. Not enough to turn it into a job, but just enough to fund the money that people typically put into hobbies. In this way, the hobby “paid for itself” indefinitely. So when my father first started really getting into photography, he also started shooting weddings and events a little on the side – enough to pay for the new toys he wanted.
Another way of looking at this is to make sure that the things you’re putting your heart into are also filling up your heart. Giving 100% of yourself to something is a wonderful way to care about it, an expression of love. You can do that if you also get 100% back. You can do it forever. But if you put more in than you get back, eventually you’re just feeding leeches for the sake of feeding leeches. Some people will be a part of the self-sustaining virtuous system, and you should give them your whole heart. Other people are leeches, and you should pull them off of you and cast them away.
All this is to say – love what loves you back.