Please Help - I'm losing strength gains??

[rossofpallion]

I've been working out for approximately 8 months now. I really enjoy it and it has helped me change my life around. My diet is great, i sleep very well and at sensible hours and i have a new hobby to focus on. Recently i seem to have hit a plateau, i do power orientated lifts and my strength gains have been slowing down massively. Today my one rep max on standing shoulder press disappeared, i'll post my workout from last week to this week..I'm only a small guy btw, so don't expect big numbers lol..This is just the shoulder press part of the workout, my shrugs are doing fine still so no need to post that..
54KG - 5 REPS
55KG - 5 REPS
55KG - 5 REPS
56KG - 5 REPS
58.2KG - 2 REPS
62.2KG - 1 REP
62.2KG - 1 REP

This week
55KG - 6 REPS
55KG - 5 REPS
55KG - 5 REPS
56KG - 5 REPS
58.2KG - 3 REPS
62.2KG - FAILED at two attemps so i done..
58.2KG - 2REPS

edit:
And two weeks ago my shoulder workout went
54KG -5
54KG -5
54KG -5
55KG -5
57.2KG -3
59.4KG -2
61.2KG 2

What the hell is going on here??

Recent changes include starting to take creatine, so i blame that for the extra rep, and i have also started to make music again through the laptop. It stresses me out but i'm just lying here sampling etc, so could that really kill my gains? My diet and sleep is fine and i laze about a lot.

[rossofpallion]

am i doing too much on that muscle group?