8 month old constantly fights sleep! HELP!

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Any tips for an 8 month old that fights sleep no matter what I do? I feed him, change him, bathe him, give him gas medicine, and give him Tylenol as a last resort... But every day for atleast the past week he’s been fighting for over 2 hours to go to bed at night! However he takes naps easier during the day... please any tips would be appreciated!