Sorry to hear about your difficulty speaking - really hard to function normally when people can't understand what you're saying. I had trouble speaking for the first week in my lower, 24/7 repositional splint, but thankfully I adapted quickly. The lower repositional splints aren't too bulky - mine was fairly streamlined and easy to get used to. It's concerning that yours is so difficult to wear- you may not derive the intended benefits if you don't wear it consistently.
I guess the first thing I'm wondering is what your specific problem is causing your TMJ. Did the NM dentist explain what the splint was going to do or why s/he recommended that particular one? Was the splint recommended to decrease pain (relax muscles), reposition the bite or both?
There are different kinds of splints and I'm wondering what specifically yours is and why your NM dentist chose it. Here is a quick 101 on different types of splints:
•Stabilization or flat plane splint. This one covers all the upper teeth. Because it's flat, it helps minimize tooth grinding and it works to decrease pain by relaxing your sore jaw muscles. It doesn't help with clenching since the lower teeth are still able to touch it. Because of the clenching factor, some people find their condition worsened by this splint.
•Modified Hawley splint. This guy fits on the upper jaw and touches only the six lower front teeth. It totally prevents the back teeth from touch and stops both clenching and grinding. A concern is that the back teeth will shift so it's usually only worn at night.
•NTI-tss (Nociceptive Trigeminal Inhibition Tension Suppression System). I think this one is less common... It goes over the upper front teeth and is supposed to stop tooth clenching and grinding. The fact that it goes over a few teeth can really stress out those teeth and possibly cause problems. It comes off at night because it's so small that there is a choking risk.
•Repositioning splint. This is the lower splint that is commonly worn by people on this site. It's called repositional because it moves the lower jaw forward or backward. It's purpose is to reposition the jaw into a healthier position and find the optimal position for your bite. For this reason it is the most aggressive form of splint treatment and it can take a good 4-6 months to start feeling results. Usually once this optimal position is found, you will experience a decrease in symptoms as your jaw is finally more comfortable. Then the NM dentist will use orthodontics (braces) to make this position permanent. At this stage, there are other options, but braces is the most common.
I had really severy TMJD and lived a really hellish existence. I had to go through a couple NM dentists until I found one who I felt offered me a treatment that would help. After a few months in my repositional splint, I felt a drastic reduction in pain and symptoms! I am now in my second months of braces and things are a lot better for me.
If you are unsure if you are getting the right treatment, I would really encourage you to find the best NM dentist in your state and get a second opinion. TMJ is so painful to experience and really tricky to treat - often the wrong treatments leave us in pain longer than need be or worsen our situation. This was the case with me and I'd hate anyone else to experience this if they don't have to.
Hope this helps...if you can, let us know what kind of splint you have and how it's meant to address your TMJ issues.
Wish you the best in your recovery