It is true that after the eternal consequence of sin has been wiped out, we are left with the temporal punishhment; however, Gid has told us how to take car of that, either in this world or the next. Do not despair, you *can, *with God’s help, atone for your sins. You have already started, by rejecting those sins and confessing them.
We can take care of the temporal punishment either in this world or in Purgatory. Here is better

First, we try to repair the damage done by our sin, giving back what we have stolen, soeaking well of someone whose reoutation we have damaged, etc. Some sins we must admit to God we cannot repair, and ask Him to do what He can.
The rest we can also do: by accepting God’s will for us gracefully and even gratefully-- giving thanks to God in *all *circumstances. And by prayer, fadting, and almsgiving.
In no way are we to harm ourselves by doing these acts. We should not give alms to the point of impoverishing those we are supposed to care for, for example. We must accept God’s will that we cannot do as much as we would like, but that acceptance mitigates the punishment, so it works out
Do not ever despair! Any problem over which despair or even just worry should instead be taken to God in prayer.