Daniel,
 
Kyle is on the money.  Its a marathon, not a sprint.  To give you some perspective for a bit of a laugh...
 
During your life you're not going to have a steady upward path in everything. You will:
 
1. lose jobs: Yep, got sacked a few years back and was the sole income earner at the time with a couple of mortgages...
 
2. be dumped by spouse: Not yet luckily...
 
3. smash your car: hah, far too often...
 
4. lose your favourite records or destroy your favourite book: common occurance...
 
5. have to move house to some place you don't like much: why do you think I'm in Brisbane now?  Work said move or get sacked again, your choice.  I moved...
 
6. get sick or injured: Still working through my shoulder injury...
 
But I'm 40 mate and still lifting, and to be honest making some of the best gains of my life.  Its a mental game as much as anything.  Even my missus told me I was fat last night which I'm now dealing with mentally.  Mental toughness will see you through.  Stick with it.
 
Cheers,
Mike