If someone who was depressed for 23 years can do it, it should be possible for anyone. I won’t lie and say it will ever be easy, so don’t worry if you think you can’t do it.
I also won’t claim that it’s possible in every environment. If you are in a shit situation, it just might not be possible. However, any situation can change, for better and worst. If the world won’t let you be happy, you have nothing to lose but your chains.
Loving one’s self might just be the hardest thing a person can do, as it isn’t one and done. However, it does get easier.
Adding to the post body: don’t gatekeep yourself from things that might help. For instance, medication might feel like you’re failing for needing it, or maybe you tell yourself it’s for people really suffering. I say, if it makes you happier, you should take it.