If God loves us then why does he make us suffer so much?
Two points– 1) There is purpose in suffering, and 2) God does not make us suffer. Probably the principal source of suffering is the result of wrongdoing–either ours or someone else’s. Alma, in the Book of Mormon, expressed it well when he said,
Do not suppose, because it has been spoken concerning restoration, that ye shall be restored from sin to happiness. Behold, I say unto you, wickedness never was happiness. Alma 41:10
There are two significant results from violating the law of God–one, we are punished for disobedience, and two, we suffer the natural consequences of our deviant actions. As an example, in Doctrine and Covenants, Section 89 we are instructed not to smoke—
And again, tobacco is not for the body, neither for the belly, and is not good for man, but is an herb for bruises and all sick cattle, to be used with judgment and skill. (D&C 89:8)
All people who smoke are liable to be subjected to the results of smoking–cancer, emphysema, high blood pressure, etc., while those who knowingly violate the word of God as given in this section of the Doctrine and Covenants will also come under condemnation for disobeying God’s word.
By suffering we gain strength of character, if we know how to bear it. We may also learn something of compassion when we begin to understand how others feel when they suffer. If unduly put upon buy others we may learn something of the sacred quality of forgiving others for the wrongs they do which cause our suffering. Thus, we may change our characters to be more Christ like.