7 week old won’t sleep

Hi all desperate for some advice. My 7 week old was sleeping in 3-4 hour stretches last week and began sleeping much better in his bassinet. But this week he’s reverted to his old ways and is worse in fact.

In the day he sleeps for about 20 mins at a time. Then at night hee wont sleep alone at all. He wakes up the second I put him down. He had one 2hr stretch but it was on me soo I couldn’t sleep.

I’m so so exhausted I just don’t know how I can keep having 0 sleep. Please help me… any tips at all? Is this normal?