No! Don't give up. Ask any writer and they will agree: the first draft is always rubbish. In the words of Terry Pratchett, 'the first draft is just you telling yourself the story'.
In fact, I would go so far as to say that if you've completed a first draft, you're ahead of many aspiring writers already. Celebrate the milestone of completing a draft, regardless of the quality.
Let's consider exactly what you think is awful. Is it the plot? Are there plot holes, implausible scenarios, contrivances and leaps? Is it the characters? Are they flimsy, unbelievable, unlikable or flat? Is it your writing? Is it boring, stilted, unnatural or overly ornate? No matter which of these – or other – problems you have identified, everything is fixable.
The first draft is just you telling yourself the story — Terry Pratchett
First draft frustrations are exceedingly common, especially for new writers who don't realise that editing is all part and parcel of the writing process. Whether you are in your first rounds of self-editing, or at the stage of hiring an editor, first draft problems can be ironed out.
Don't be surprised if your first round of self-editing changes some pretty major aspects of your novel such as a different ending, a death in the cast of characters, scrapping entire scenes. This is perfectly normal. First edits give you a chance to fix some of the major plot and character problems you have identified.
Get it down. Take chances. It may be bad, but it’s the only way you can do anything really good. — William Faulkner
If your main concern is your prose, style of writing, language choices and sentence level work, this won't be tackled until later edits.
However you choose to identify and work on the issues within your manuscript – whether through using a beta reader, friends and family, writing circle, book coach or editor – just know that you are not alone. First drafts are rough. First drafts are not for publication. First drafts are just one part of the process.
As the ever inspirational and eloquent Ernest Hemingway said, 'the first draft of anything is sh*t'.
Keep going. Keep writing. You will get there.