Painful contractions but not dilating

I’m 40 weeks 5 days pregnant. Woke up yesterday to very regular contractions that lasted for 2 hours so I called the hospital and they told me to come in.

They told me I was 3cm dilated. Contractions continued to pick up all day and were about 5 minutes apart. Labour and Delivery beds were full so they gave me something for pain and sent me home.

I’ve now been contracting for nearly 36 hours. They are very painful. Sometimes 5 minutes apart and sometimes 15 minutes apart. I’m scared they won’t admit me unless my water breaks or I’m more than 3cm dilated.

I’m exhausted, I can’t sleep through the contractions. What do I do?