Trying to break bad sleep habits—thoughts?

So our precious 8 week old little boy is struggling with a good sleep routine (which means we are too!). Early on, starting week 4, we would get solid 5 hour stretches in the night. Now, however, he has reverted back to wanting to eat every 3 hours or so during the night. During the day for the past month he doesn’t sleep by himself. He is always wanting to be held during the day and has been getting less than 12 hours of sleep a day for two or so weeks now. Our pediatrician recommended today that we let him cry it out for 20-30 minutes to see if he will self-soothe but I’ve never believed in the crying it out method. At this point, I will give it a try but I wonder if anyone else has experienced these sleep challenges and if you did anything else to break bad habits and get good sleep during the night and day? Thanks for your help!

Sincerely,

A tired mama