Paul lets Timothy know that in the future people will stop believing the truth, but he should continuing trusting God's word even when he is persecuted.
Possible meanings are 1) this is a time later than Paul's time. AT: "in the future just before Jesus returns" or 2) this refers to the Christian age, including Paul's time. AT: "during this period of time before the end"
Here "lovers" refers to brotherly love or love for a friend or family member, a natural human love between friends or relatives. This is not the kind of love that comes from God. AT: "self-centered"
"impulsive" or "foolhardy." This describes people who do things without thinking about the consequences or even though they know that bad things could happen as a result.