How long have you been taking lexapro? If it's been a month or so, ask to try a different medication. I've taken several different ones over the years and know that some work and some don't work for me. Do not stop taking the Lexapro without your doctor's supervision. Stopping cold turkey can sometimes result in worse symptoms than you had when you first started taking it.
It doesn't matter what you call it, having the blah's and being easily irritated is no fun for anyone. Have you tried exercise like going for a walk every day. Do you get out of the house? Are you interested in doing anything in particular? Depression presents in many different ways. Perhaps you're thinking depression is feeling sad and wanting to cry. That is just one way it presents its self.
If you don't exercise, eat a balanced diet, and have an interest then try cultivating those activities. See if that helps.
How we feel and respond is directly related to how we think. Try, when you find yourself feeling irritated, telling yourself something positive about that person. Focus on positive ideas and get rid of the thinking that leads to irritation.
Perhaps make a list of everything that irritates you about your husband and uncle and then make a list of everything that you like about them. See if you can find enough to like to ignore the irritation. Also, underline the things that irritate that you could discuss with the person and perhaps change either the way they do something or the way you think about it. I've found that being able to talk about irritations with the other person helps me let go of the irritation even when nothing changes.
If you and your husband don't have date night, try that. You need to have good times with him to balance out all the stresses of parenting.
You mention not wanting to get up and clean. OK, don't clean but find something else as an incentive to get up. You're naturally tired. Allow yourself time to rest without feeling guilty. At the same time be sure to balance the rest with interesting time awake.
Perhaps counseling would help you. If nothing else, talking with someone would clarify for you what is going on. That in its self would be helpful.
Later: I had a thought related to my own experience. I used to clean all the time too. When I stopped I realized that my cleaning was a way of handling my anxiety and depression. Could you now be more irritable because you're not using the cleaning as an escape from the frustration? You're naturally too tired to clean and it's good that you're doing less. Perhaps finding another outlet for your feelings would help you be less irritable?