I also have difficulty expressing how I feel to people (at least verbally)...which is why I'm not "supposed" to be writing

Like FavoriteJeans said, just start slowly. I started with the receptionist at my T's office She complimented me one day, and I brushed her off. The next week I wrote her a letter apologizing for brushing her off and thanking her for the compliment. That lead to many small verbal interactions.

You can also reflect off of what someone else says. If someone say: "This weather is really depressing", you can respond with an agreement (Yeah, cloudy days make me feel like I have no energy), a disagreement (I love the rain, it makes me feel like everything is being washed clean), or an opposite agreement (I prefer warm sunny weather...brings back good memories of summer).

You don't need to dive deep into feelings. I think it's more about relating with others and learning how to better verbally communicate.