Such a tough question to answer - as Kim pointed out, you have to focus on the positive. Keep in mind social work is a field that is very undervalued in our current society, and you're working with underprivileged people in (likely) the worst times of their lives. So, it isnt an easy job, and one where high burnout is very common. I've worked in a slew of crisis/high stress social work positions, including er cps which it sounds like you're familiar with as far as how it might impact the family you're helping. You are often given a very high case load, and might not always have the ability to see the impact of what you're doing. So from that perspective, it can get very hard. There's a lot of 'hard truths/reality' out there that you will be exposed to, you will be asked to do more than is reasonable because the system is overworked and under supplied with workers, and you may never know if what you did made a difference. Its likely the people you talked to are in that spot.
So how do you not get turned off entirely (because if the world is this broken, it definetly needs us big-hearted people!)? Well, you can look for jobs that provide you the long-term perspective, so you can see your impact. Also, you create really healthy boundaries (remember, you will be forced to take care of yourself over others even when it makes you feel guilty, because if not, you WILL cause yourself harm in the end). Ask for and create a supportive work environment and community. Sharing our woes with coworkers is so crucial to not getting beaten down by the hardships we see every day. And lastly, celebrate every possible win you can, no matter how small. My first 'win' was at my internship as a school counselor, were I saw kids who had very hard lives and not a great chance of success. But after working for weeks with one client who was severely depressed, they came in one day with the biggest smile because "today my mom was nice to me" (I'd been working with her on boundaries and reframing). A smile is so little...but to me (and of course the client!) it meant the world, even if it was only for that week, that day, etc. Hold on to your wins, you'll need to survive what is otherwise a difficult job only the strongest of hearts can handle.
*hugs* you got this!