Yes, teachers and meditation retreats could be helpful. But just bear in mind that there are lot of different ones, and they're not interchangeable. I'd suggest you do a lot of research and talk to some people you respect and trust who've been to the retreat/teacher you're contemplating.

Also, I can recommend a couple of books: The Heart of Buddhist Meditation and Mindfulness in Plain English.

I had also tried meditation for years and never "groked" it. What ultimately helped me was using "One giant mind" app. It has 15 minute session for everyday. Doing it everyday for a week I didn't feel anything different but one weekend on a whim I decided to meditate using the app for 3 hrs straight and that's when I felt I finally got it.

Like others have said you can take help of teachers or try meditating in a group. Although I do feel because there so many choices available discovering what works for you may require a little bit luck too.

Meditation isn’t easy. I never saw it’s power until 6 days into a Vipassana retreat where you do nothing but mediate, eat and sleep, including no talking or reading.