穷思苦想

to think hard (idiom) / to give sth much thought

to think / to believe / to suppose / to wish / to want / to miss (feel wistful about the absence of sb or sth)

to think (about) / to think of; to devise / to think (that); to believe (that) / to desire; to want (to) / to miss (feel wistful about the absence of)

bitter / hardship / pain / to suffer / to bring suffering to / painstakingly

to think / to consider

poor / destitute / to use up / to exhaust / thoroughly / extremely / (coll.) persistently and pointlessly