。
I have nobody to talk things over with.
Literal
I [to-は] consultation partner [subject-が] not-exist.
相談相手 is a compound noun: 相談 ('consultation, discussion') + 相手 ('partner, counterpart') = 'consultation partner' = 'someone to talk things over with.' A slightly melancholy statement of loneliness, common enough in casual speech. には adds 'as for me, at least.'