Brief Answer:
A cervical collar would be best.

Detailed Answer:
Thanks for the query.
I have gone through your query and photographs attached.
1. When you on a sitting try to extend your neck so that your cervical spine is straight. You can use a “soft cervical collar” available in medical shop for the same. Avoid rapid flexion of neck.
When you sleep do not use pillow.
These are the recommended posture in cervical spine.
2.Doxynate is generally used for vomiting during early pregnancy. You can use drugs like ondenseterone(Emeset) or domstal. If vomiting persist we have to evaluate to find out the cause.
3. You can take foods with low glycemic index. Avoid cold beverages and ice creams. Canned foods and fries have to be avoided. Include more fruits and vegetables in your diet. Reduce rice and shift to chappathi.
Hope I have answered your query.
Wishing you good health.

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Brief Answer:
Given

Detailed Answer:
I was mistaken cervical spine for cervix!
I thought you were talking about short cervical spine or short neck.( You attached a pic of neck also!)
Coming to short cervix. You probably had undergone cervical cerclage procedure. You can go for any sitting and supine position post procedure. It won’t affect.
Thanks


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Brief Answer:
You can do.

Detailed Answer:
You can continue lotus yoga position otherwise known as padmasana.
No issues.

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