First, if you haven't already done so, you NEED to start documenting his behavior. Write down each time you and he discuss visits, your offers for visits, whether he accepts the offer, when he requests visits, etc. Take pictures of anything relevant to evidence his behavior. Before it escapes your memory, write down the specific dates and times when you have witnessed him driving under the influence or observed evidence of his drinking and continue to document it going forward. Ideally you would see him drunk driving first-hand, not just evidence of his driving (i.e. he and his car get back home somehow, but you can't necessarily say that it wasn't a friend who drove his car). Find credible, neutral, witnesses of his behavior to write affidavits if you can.
Second, it WILL be a difficult fight if he has retained an attorney and you have to self-represent. His attorney will (presumably) know all the rules you don't. His attorney will know how to request more time, how to file responses, how to make you "lose" on a technicality. His attorney knows all the statues that make your logically sound and valid arguments moot because the law says blah. If there is anything in your power that you can do to retain a quality attorney of your own, do it. Borrow money from everyone you know to pay the retainer (you can make a payment plan for the rest). Don't quote me on it, but depending on the lawyer and his/her experience, you're probably looking at a $2,000-5,000 retainer. It is a lot! But it is very important because the initial ruling sets the bar and is even more expensive to fight to change later.
Finally, and I know this part is going to be hard for you, know that it is very normal for a child to have a hard time transitioning to their non-primary caregiver's home. Being tired, upset, and clingy are unfortunately par for the course, and it will get better with time. When a parent doesn't have much time with their child, they tend to overdo the activities, which doesn't leave proper time for rest, and when she gets back to you, she is understandably clingy because she missed you. But it's not a justification to withhold visitation or even to reduce it. What is necessary is to suggest a plan (to the court) to fix that problem. You look reasonable if you counter his request for 50-50 with a specific plan for increasing parenting time from what it is now (almost nothing) to what is reasonable for your child (whether you want to argue that 50-50 or 80-20 is a reasonable goal is your prerogative). You can suggest parenting guidelines, such as maintaining her nap and bedtime schedule, and include your specific concerns such as the alcohol problems if you are able to document them. The driving intoxicated is a relevant concern if he does it with the child in the car but as far as the court is concerned, if he doesn't do it with the child in the car it doesn't necessarily mean he's a bad parent. Yes, I know, if someone drives drunk without passengers, what's to say they won't do it with a child ... believe me, I'm not saying this because I believe it, I'm saying it to be realistic of what you're up against. Instead you suggest provisions to protect your child, such as if MOM smells alcohol on DAD's breath when he arrives to pick up the child, that visit shall be canceled (preferably phrased more eloquently).
You've left out details that are necessary to give suggestions beyond that. Is there a custody order in place already? Has he already established paternity? Have you already been served? Do you have a feeling of what his real issue is (e.g., to avoid child support)? Do you think there is any circumstance in which he will come to an agreement with you out of court? Are you comfortable sharing what state you are located in (the laws vary widely from state to state and even moreso between the US and other countries)? I hope I don't sound too negative or deflate your sails too much--hope is not necessarily lost, but without a couple pieces of the story, it's hard to point you in the direction of the hope and optimism.