7-8 hours of sleep in the night is considered a good average. During the day you should try and get some short relaxation spells even if not means a few minutes of keeping your eyes closed and doing deep breathing. For getting better sleep at night have a small cup of warm milk, urinate immediately prior to bed time, avoid intake of too much water close to bed time and use pillows to support your back, abdomen and legs. You can consider a pregnancy body pillow and wedge pillow or home pillows are good too.