Will steroid injections and massage fix my eyelid back to its prior almond shape? Or will I need a retraction surgery?

Could you please add some photos?Steroid injection does not seem a good option, bettter options like 5 -fu can be try.

This is a complex issue and need photos and evaluation to determine accurately. See an oculoplastics expert experienced with this issue.

There are various reasons for post-blepharoplasty lower eyelid retraction, ranging from issues starting from the front of the eyelid all the way to the back of the eyelid. Sometimes it's just 1 issue, sometimes a combination.
I don't typically inject steroids alone, because it's not enough for scar modulation and can pose other issues. I instead use a combination of dilute steroid and 5FU, or just 5FU alone. These are off-label uses of the medications.
I also give my patients the opportunity to opt for nonsurgical treatments where reasonable; many patients don't want revision surgery, or aren't ready for it, and I've had cases where for example filler alone has kept patients happy. Again this is in a select group of patients and not for everyone.
You need an in-person exam for proper evaluation and recommendations.

A steroid injection is unlikely to resolve a lower eyelid retraction after blepharoplasty. That applies to a steroid injection plus "massage like crazy." The steroid can also cause fat atrophy that is often unhelpful. For that reason, 5-FU is more favorable for modifying scar. Generally lower eyelid retraction is not caused by just scaring. It is caused by lack of lower eyelid and top of the cheek at the orbital rim. It is caused by infracillary incisions that damage the motor nerves to the lower eyelid with loss of the hammock function of the lower eyelid. It is caused by the excision of tissue associated with infracillary incision procedures. Antiinflammatorties can modify and soften scar but they are not miraculous treatments. Most of these require reconstructive surgery. I am attaching a link to my website that talks about how these are managed. I am also linking a video on this subject. There is no substitute for a detailed personal assessment.