...and everything is perception.
If you start your language course with dread and negativity, it will probably feel difficult.
We are programmed to see what we want to see: in people, in situations, in books and movies - even in the purely geographical meaning, as in the location of that little place in the mall you never noticed before, until you went searching for it! Sure, you'd passed by it hundreds of times, on your way to some place else - but you never saw it; you were too busy going to the supermarket.
Once we make up our mind about a person, we only acknowledge their actions and qualities that prove us right: aha, he left the office early, typical! If he was early to work, though, we are likely to neglect that fact. It doesn't serve our purpose; it doesn't fit into our plan. On the other hand, our dearest friends, no matter how many mistakes they make, remain our friends - because we have accepted them as they are, and we tend to remember what they did right, rather than what they got wrong. There's the secret to a happy relationship!
So, the way you approach your new language learning experience is crucially important. No pressure - but you will be more successful, more relaxed and more satisfied, if you jump into it as if it's a new adventure (it is!) on which you're embarking with new people - or friends and family - and one that is going to make you a more knowledgeable, more tolerant, better-adjusted person. It's going to bring you that raise at work, too. All this, on condition that it is done right.
Learning a second language (or a foreign language) widens our horizons. The very fact that we try to understand a different logic, structure, culture and even mentality, expands our boundaries and gives us a sense of discovery. Let's see it that way!
In my favorite context (grammar), I would really like you to see your new language as a "must" - internal need and importance - rather than a "have to", which expresses external obligation. Of course, improving your English for work sounds like... well, work - but it doesn't have to be a chore.
Get into it.
Warm up to it.
Let it grow on you...
There - you're learning idiomatic expressions already! Good luck and good attitude!