I find it (adjective) to (do something)

This phrase is used to describe opinions or feelings that you have. It's a slightly educated and formal-sounding phrase that you use to emphasize that what you're describing is your personal experience, not a suggestion that you are making to the listener. Another way to explain it is "For me, it is..."

For me, it's hard to relate to him sometimes.

Here are some other examples:

I find it interesting to sit outside and watch the different people walking by at lunch time.

The word "hard" is especially common with "I find it":

I find it really hard to focus on my work in the afternoon.

relate to (someone)

To "relate to" someone means to feel comfortable with them, and to understand each other. People usually "relate to" each other by sharing information about themselves.

If someone always wanted to talk about sports, but you weren't interested in sports, you might have trouble relating to them. Here's another example:

I was glad to finally meet someone who I could relate to.