I can understand the agony you are going through, but, you need to have a little patience right now.
Firstly, I would suggest, you take a break from taking your vehicle to work.
Secondly, you will have to make the adjustments for your seating arrangement and the height of your working space as well as the drawers and shelves that you use the most. It would also include your telephone. Change the sides of your telephone every month. All this will be a must for you, since you spend 8-10 hours there every day.
Thirdly, take frequent breaks at your computer.
Fourthly, do get your reading glasses, if you have and your eyes checked.
I think a physiotherapist should be able to help you. Learn all the neck and shoulder girdle exercises and also hand and wrist exercises and do them regularly and as you improve, you can reduce the no of times you do the exercises. Learn the ergonomic principles for your daily activities too.
Since you are tall and are having the pain in your thigh too, please learn back extension exercises too.
When you improve, start taking your vehicle twice a week and gradually get back to your routine. Learn to relax.
After you are well, I suggest, you take up a sport of your choice where you can devote your time at least twice a week. This will be a good change for you and will keep your body muscles and joints in good shape to take up and unwanted pressures. It’s just a matter of time. You will be fine.