I am sorry to hear you are worried about your dog.
My name is***** am a veterinarian and will do my best to help.
How old is your dog?
How long have the bumps been there?
Is he (she?) eating, and drinking normally, or in addition to being lethargic, is he eating less as well?
Lumps under the skin can be infections, parasites, allergic reactions. If this were my own dog, I would look at the discharge under a microscope, to try to determine what they are, and the best way to treat them.
Being lethargic could indicate a fever, and that these may be infections, and he may need antibiotics. Lethargy can also be a sign of anemia, pain, internal illness. It would help to know if this is a puppy, a young dog, or an old dog.
I am not seeing responses from you.
I hope you can see what I am writing!
I will try to connect with you another way, if I do not hear from you soon in live chat.