Hi there! I don't have any experience in this area. I have felt like this on a few occasions myself, but it seems to wash off after a while. Sorry, if what I say is ineffectual or naive, but I'd like to give you some support.
Can you trace back when you started feeling like this? Is you little boy being difficult in some way? Are you having problems with work/being at home with him (what is your situation?)? How are things going with his father? Is there a relative who can look after your boy? Anyway you can get some time to yourself to reflect and try to recover? Can you get to the roots of what has caused these feelings?
Do you feel up to trying to get yourself back to where you were? I know that when I am feeling down, the only things I have energy for are working and driving, strangely. Maybe as they distract me from the real things that get me down. I am a teacher have noticed that when I have time on my hands in the holiday I can become very down. Then it is only me and DD as DH works nights - maybe a similar situation to yours? DD is 4 and takes alot of energy that I don't have. I am far happier during term time, no matter how much work I have. This makes me feel really guilty and makes things worse, but I have learnt at the beginning of term time, when I am fresh to put a few techniques in place that help.
I pray - not religious but it helps to acknowledge what I am grateful for and what I need help with. Then I try to do guided meditation (use the headspace app). And finally I think of 3 things made me happy that day. I read this research that said if you, at the end of every day, reflect on 3 things that made you happy with a reason (essential, e.g., not "I am happy to have my son", but "I am happy that my son made me a card at school, which shows how much he loves me") then you were much more content after a month. I try to do those 3 things - pray, mindfulness and happy list - every night. It does help. Also if I could muster the energy, I would do exercise as I believe that is really good for mental health.
Also, I read from the eminent Raj Persaud (from This Morning - about 15 years ago) that you should try to have 5 areas of you life, e.g., family, work, hobby, friends, extended family. Then when one area breaks down, you have the other 4 areas to rely on. Each area giving you an interest, support or way of boasting your self-esteem. This is my problem. I have moved abroad and lack friends, family and money/time for an interest (I did try gardening, but that literally died a death!). Do you have a network to reach out to?
I hope that things work out for you. Only you know if "homemade" tips like this can work, or you need more medical help. 