Sleeping is a nightmare now

So my son is 8 months and he has been sleeping through the night since 4 months but now he has been waking up every hour on the hour wanting to be rocked or something tonight he has woken up every 20 minutes I’m so tired of it honestly he goes to bed at 9 he last nap is over at 430-5 so I know he’s tired I just don’t know what to do at this point I’ve tried letting him cry everything and nothing is working. Honestly I just want a little time to relax and be able to sleep a solid night