There are two reasons why you mightn find it difficult to speak English:
1: It's a difficult skill (compare it to reading, for example)
2: You don't practice speaking enough (think about typical language lessons)
Think about it. When speaking, you have to use the right words in the correct order, speak clearly and accurately, and also be able to understand what the other person is saying.
Most learners don't get the practice that they need.
Here is how to improve:
1. Work on your pronunciation - do that through my program:
https://www.tofluency.com/tfp/2. Use the To Fluency Method: also inside my program
3. Shadow native speakers (but be careful about how you do this)
4. Get natural practice
Commit to doing this each day. Try the different methods above and find out which one(s) works best for you.
To learn more about these methods, watch this video:
https://www.youtube.com/watch?v=Z7PGRbvJBkQ