ROM Disability

I have Erb's Palsy in my left shoulder/arm that leaves me with a severe lack of ROM - I can lift my arm straight out, horizontal & even with my shoulder, but my elbow will not straighten so my forearm is always near my body (almost a more narrow '<' shape, the point being my elbow)

I also cannot lift that elbow above my shoulder without using my right arm to pull it as straight as it will go (never fully extended)

I am not able to put weight on that side (push-ups, planks, etc..) and when I do a curl, the left arm will not go straight back up, it comes in towards my chest (like saying the pledge, only opposite, lol)

SOOOO - I'm worried that my arms will be disproportionate! Is that crazy?? Does anyone have any experience with anything similar to this?

Erb's Palsy is not treatable, I can work on flexibility and expanding my ROM but doing that won't ever give me a full range of motion.

I would like to eventually see a physical therapist, but I'm currently working part time at min wage with no benefits and not likely to get any in the near (or far) future.