Hello. No, I would not recommend a strap for the neck. With prolonged used:
1. You develop dependence
2. Your muscles become weaker.
Next Steps
Find a good physiotherapist near you, and have a few sessions with him/her for postural correction and to get educated about proper ergonomics for your job- type.
Health Tips
Stretching your neck, back and shoulders every 15mins is a must (if you have a computer-based job). Exercise your eyes daily too