Go for it. You have about a 30% chance of a cure; but, even if not cured, you should be significantly lowered. And, after the steroids, you might consider hyperbaric oxygen.
Here's a journal article from September, 2013, describing injections for acute tinnitus:
The Prognostic Factors of Intratympanic Steroid Treatment for Acute Tinnitus
Hyun-Joon Shim, (presenter)
Yong-Hwi An
Hyun Woo Kang
Sang Won Yoon, MD
Abstract
Objectives: We report the better therapeutic efficacy of intratympanic dexamethasone injection (ITD) in patients with acute subjective tinnitus (AST) compared to alprazolam medication only. The present study aimed to determine the prognostic factors of ITD injection for AST.
Methods: A total of 139 subjects who underwent treatment of ITD injection for AST from 2009 to 2012 were enrolled. The relationships between treatment outcomes and various clinical features or audiometric findings were analyzed retrospectively. Three months post-treatment tinnitus questionnaires were completed in 90 patients. Audiologic response was defined as hearing threshold recovery greater than 15 dB in any frequency of the pure-tone audiogram.
Results: Tinnitus completely disappeared in 43 patients (cure rate = 30.9%). The mean duration of symptoms and initial tinnitus loudness score were significantly lower in the cure group than in other groups (P <.05). In the cure group, the number of patients with asymmetric hearing were larger than the number with symmetric hearing (P <.05).The mean improvement index of tinnitus was significantly higher in the unilateral tinnitus group than in the bilateral tinnitus group (P <.05). The audiologic response following ITD is more frequent in the patients with asymmetric hearing than in those with symmetric hearing (P <.05).
Conclusions: Duration of symptoms and initial tinnitus loudness score might affect the cure rate of AST by ITD injection. Audiometric asymmetry and unilaterality of tinnitus are preferable factors of ITD treatment for AST.
Reference:
http://oto.sagepub.com/content/149/2_suppl/P235.2.abstract
I am generally sceptical towards steroid injections as a simple lumbar puncture resulted in huge inflammatory reaction in my spine, however I am considering orals. But I think that even if I opted for a injection I would not be able to find a qualified doctor to administer it in my country.