I Was Given 100 Mg Lamictal, 300 Mg Of Wellbutrin

i was given 100 mg lamictal, 300 mg of wellbutrin xl for bipolar about 3 weeks ago for bipolar. a few days after those intitial doses, i was given 30 mg of oxycodone for my up coming hip surgery due to hip dysplasia. i abruptly stopped all of them last sunday. on monday i decided to continue with only 50 mg of lamictal incase i had a manic episode. i did not feel too well for a few days but continue to feel extremly tired/lethargic. what is going on?