Hi, I had earlier asked few questions above so that I can gather additional information related to your health concerns about twitching of the thumb. It is possible you are encountering some technical glitches to access this site properly or you may be busy now and not in a position to reply, so what I will do is post an initial answer here based on the amount of information I have received through your initial question here, please go through it when your time permits & when you can, and please get back to me if you want to discuss this further.
Based on the information you have provided in your initial question this twitching involving the thumb is unlikely related to any serious underlying health conditions, rather as mentioned earlier above this is due to some benign issues like stress or anxiety disorder etc so please not to be scared.
And the observation that you can stop this twitching by pressing certain points on the thumb also indicates this must be some benign condition like anxiety or stress causing this twitching but certainly not any serious illnesses.
This is expected to resolve soon, if this persists then you may try to see your neurologist for the further evaluation and investigations but I once again strongly reassure you this twitching certainly does not appear to be related to any serious underlying health conditions rather it is related to stress or anxiety etc.
Please go through the above answer which is based on what information I had gathered from your original question. If you want to discuss this further or if you need any additional clarifications please get back to me, and also please try to provide me the additional information I had inquired earlier through the questions I had posted above and I am available here for further discussions until you are satisfied. And please click a positive rating (preferably 5 Star/Excellent) to credit for the time & effort put by me in answering your health question, and this is the only way I will be credited for my service to you. If you have follow-up or additional questions you can ask them after the rating too.