Hi there,
I absolutely believe you have every right to invest in yourself. When you're healthy and content, you'll have more energy to give to others as well. Whether you choose to do so or not is, of course, up to you. I think maybe people who have a lot but never choose to share any of it with others could be called selfish.
But I believe there's also good selfishness. I used to be the kind of person who'd do everything and anything for others while completely abandoning myself in the process until I became ill and was of no use to anyone anymore. That's when I chose to focus on myself. There have been times when I've wondered if I'm too self-centred and have felt guilty about it, but for me, there simply was no other alternative - I'd hit my personal bottom and felt I wouldn't have a life soon if I kept going the way I had been for so long.
I'm an extremely empathetic person but I feel like I'm now developing a healthier relationship with the give and take. I'd never work my butt off and give ALL my money to others. The same goes for my time and energy. I think it's about balance as well as personal boundaries, and setting those is HEALTHY.
I do enjoy giving what I can when I can, though

There's an animal sanctuary that I visited once and immediately got a very good vibe of the place. I've followed them on Facebook for years, and they're excellent at presenting what they do. I totally believe in them and have realised it really doesn't matter how small an amount you want to donate, it all counts. And there are few things better than seeing the amazing transformations when the animals get better!
I also find there are 'causes' or problems I care about more than others, and I think it all comes from each person's experiences. People who have experienced poverty themselves might be most affected by those stories while I'm most affected by stories of child and animal abuse. I think this is natural and believe there will be enough people caring about each cause. The more that get excited about helping others, the better! But within our own personal means and energy levels, of course