Jenna70,
Just let me get the time line straight. You don't say when your injury was, but you had surgery 4 weeks ago. From the hardware that was placed, it sounds like you had a shaft fracture (which can be difficult to get to heal). Two weeks ago you had the surgical dressing and stitches removed. Currently you are nonweight bearing.
Your "splint" is internal. By placing the internal fixation, the need for a cast is decreased. This allows the person to begin range of motion of the ankle and foot as soon as possible, decreasing the stiffness and atrophy of being in a cast.
It is usual to be nonweight bearing for this type a fracture, until there is enough callus formation. That can, in rare cases, take six months. But, usually it is more like 2 or 3 months, depending of course on the person's healing capacity and whether the person smokes.
You should have a routine follow up scheduled with the surgeon. If not, make one. You need to discuss the options for physical therapy and the weight bearing situation. It is very unusual for it to be six months of total nonweight bearing. See if you can start pool therapy. It is very helpful for getting range of motion and strength back in this buoyant environment and the moist heat helps with the circulation. Doing range of motion excercises also helps promote circulation. As does elevation. A limb that is held down and not moved, will often become cold, whether it is injured or not.
Discuss your concern for not having some type of external splint. Though it is probably not necessary, many patients feel more comfortable with a light, removable splint for the first few weeks. Just don't become dependent upon it and lose range of motion.
If you feel that a second opinion is necessary, by all means get one. (Just remember, a surgeon may be hesitant to take on another surgeon's post-op patient.) If you can not establish a good doctor patient relationship, try another surgeon. However, I would get a follow up appointment as soon as feasible and discuss your concerns with the surgeon. Make sure you understand the post op rehab plan and have all your questions answered.
Good luck