Beginnings are always hard. That’s just one of those truths about writing. It’s not a failure as a writer, whenever you’re starting a project, the beginning will almost always be the hardest, and require the most revisions later.
When I was younger, I used to deal with beginnings by not writing them first. I’d start about 1/3 of the way through the piece, and then go back and actually rough draft the beginning after the fact.
There’s actually some decent arguments for this approach. Minor mistakes are more likely to be discarded by the reader without coloring the entire story, for them. You’re writing the part of the piece that needs to be strongest once you’re deeply invested in the work. But, you’re also drafting fragments of your story in isolation from the whole, and then trying to get everything to line up, which is a lot harder than it seems. It also creates a situation where, if you’ve screwed yourself, you won’t know until you’ve already invested a lot of time in the project. Finally, I’m not convinced it actually is easier.
You start with a little less pressure, but, in the end, you’re still going to have to suffer through the first portion you write, regardless. Just because it’s not chronologically first, won’t really save you.
The only reason this ever worked for me was because I always make sure I’ve got a fairly solid outline in my head before I start writing. And, back then, if I came up with a better idea once I was working on the early pieces, I was usually stuck with the original plan.
These days, I always write with one eye firmly on “what’s next.” When I’m writing an opening, I’m thinking about the followup, and in parts, what follows that. It takes a lot of pain out of writing the opening, but it’s also more time consuming.
Either way, starting on a piece is always going to be difficult, because you’re setting the tone for the story. The best advice, whatever your approach is; “everyone’s rough drafts suck.” It’s just a fact of life. Know where you’re going, set out, then clean it up in revisions once you’re working on your second pass. Also, be ready to revise the hell out of your opening, because it is the hardest thing to write, and it will take the most work, long after everything else is done.