Ok, first up your goal I guess is mass, so in many respects strength is a nice to have rather than your key aim.
Having said that, strength increases typically go hand in hand with mass gains ( though not necessarily in a linear fashion), so I think your cycle has run it's course for sure.
Personally I would do a strength orientated cycle now (3 months, dropping poundage down some at the begging of each month), for a number of reasons.
It's nice to see yourself getting stronger and your strength matching your looks.
It tends to focus you on basic lifts and progression in poundage.
It sets you up nicely for superior gains on your next mass cycle.
You can come back to this routine in the future and compare your progress to date with ease.
What not to do.
Add more sets to your current routine or days per week.
Changing barbell curls to dumbell curls and using your max poundage in the first session or similar nonsense.
In essence ease up, then build up, with the same core exercises.