I agree the TSH level is slightly raised, but the T4 level is well within range.
This suggests you may be at risk of developing hypothyroidism in the future.
I see that in a previous post in June Sqad has suggested you need a repeat test in 3 months.
What does your GP say? There are other reasons for tiredness and weight gain.
How did you get your readings? I've had an underactive thhroid for 10 and have been on medication all that time yet have never ever been told my results