There's a few things you can do, find a cleansing that works best for you. Burning sage can cleanse the house. Be strong and tell them to leave. After cleansing cast a protection spell [again, find the best one for you] to keep the spirits and negative energy from returning. From there, relax and forget about them. If you hear a noise and think 'they're back' this creates doubt and eventually can let them return.
After the cleansing/protection [and you should cast one on yourself too] I would try to find balance and calm. Meditate, journal, drink lavender tea, are some ways to relax and find your center.