SAHM- beginning to realize

After 4 weeks on maternity leave I am beginning to realize I can't be a SAHM. I am not a nice person after being home alone all day with a baby for 12+ hours. I am crabby to my husband when he gets home and by this time of the day very frustrated. I will enjoy the 4 months I have at home with my son, but I will be excited to go back to work part time in August. I will be a better wife, mother and person then.