Girls, I have such a problem that my child almost doesn't sleep during…

Girls, I have such a problem that my child almost doesn't sleep during the day. For example, he stays awake for 2/3 of the time, after which he sleeps for a maximum of 25 minutes, then again for 3 hours of wakefulness, 20 minutes of sleep and so on... He goes to bed at 10 am and wakes up at 10 am, half a time I give him breast milk at night. How can we deal with daytime sleep? I tried not to let him sleep so that he could withstand longer periods of wakefulness, but nothing works, he gets fussy and wants to sleep. Such a regime has been with us since 2 months...