Can God Use You to Help Others When Your Own Life Is Full of Problems?

Yes.

Consider Paul’s life.  He very rarely had it easy.  You probably wouldn’t want to trade lives with him.  Yet God used Him greatly!

Jesus helped a lot of people despite being around an embezzling treasurer, disciples who argued about who was the greatest and often didn’t believe His words, Pharisees who wanted Him dead, people who got healed and then disobeyed His instructions to keep the matter quiet, people who lied about Him and large crowds that gave Him little rest.

So you can help people even if you don’t think all your ducks are in a row yet.  In fact, the ducks might become colinear sooner if you sow into the needs of other people because God guarantees that you will reap whatever you sow.  Job probably had more problems than anyone else, but he was healed when he prayed for his friends (Job 42:10).