Sanity check, is it autoimmune?

I (27M) went through corticosteroid treatment 3 times over the last 6 months and every time I taper off, it comes back. First it spread from my right to my left eye and most recently my right eye’s pupil began to stick a little.

Chest xray and infection blood tests came out clean when I first got them 5 months ago.

Yeah sure I’ve had back pain for years but it’s mostly my upper back, shoulders, and neck. I was always told it’s my bad posture from looking down at my phone, sitting all day at a desk, and not stretching enough.

Are there other reasonable explanations other than autoimmune? I’m waiting on an appointment with a rheumatologist and uveitis specialist.