The main thing is to start understanding your own neurotic patterns. We constantly move between wanting and avoiding things, from small attachments to our thoughts and habits, to strong dislikes. The more you understand this pattern, the more you can let go, and the less your daily feelings will disturb you. As that happens, a natural joy will start to appear. The truth is, 90% of what triggers your emotions today will be gone in hour, 98% within a day, and 99.9% won’t matter at all when you die.
The biggest step is realizing this pattern. Training it comes through awareness. Then, stepping outside yourself helps a lot. Doing things for others, like helping with food serving or similar directly useful things, takes you out of that self-focused mode where everything is about what you want or need. It feels like a hack, but doing things for others is natural for humans.
Something that's common in the west: an empty feeling, feels for people like the truth. But it's often a self oriented way of thinking with a subtle form of aversion. This is why often things like sports, friends or helping, can take people out of this way of thinking instantly.
Meditation can also help. I’d focus on less rational forms, with compassion and visualization, since they make it easier to connect with a sense of meaning. The issue here with the Western approach is that it's all goal oriented: less stress & more success. This goal oriented approach reinforces self-obsessed thinking; which is why lots of spiritual paths tend to focus on doing it for others to avoid this trap. In the beginning this is a bit of a trick; at some point it will be natural.
And lastly, understanding that life moves in waves, with ups and downs that always come and go, helps you stay less attached to your own thoughts & feelings in your reaction to life's events; and then life events will have less impact on your mood.
A few mindful experiences with psychedelics, used with the intention to see life’s patterns, can also offer insight. They can help you find meaning instead of falling into nihilism when you realise everything is impermanent (which most people already have).
The difference with such an approach vs western conventional therapy is that it's not focused on the content of your thoughts & feelings but starting to let go of the seriousness of them in general. They are not mutually exclusive.