Does what occurs in the chest, such as self-talk, count as an intention, and is it permissible to count the number of times one performs Wudu to be sure?

The intention for prayer or ablution suffices by bringing it to mind in the heart at the time of the takbīrat al-iḥrām (the opening Allahu Akbar) or when beginning ablution, and you do not need more than that. What you are doing by way of intention is sufficient, and your ablution and prayers are sound. Do not give in to obsessive thoughts (waswas). The intention is to specify the prayer (whether it is Ẓuhr or ʿAṣr), and you are bringing that to mind. If the question about the number of times for ablution refers to regulating the number of washes for each limb, then this is required to achieve a strong presumption that the limb has been washed three times if one intends to wash it three times, and washing three times is recommended, not obligatory. The best cure for obsessive thoughts is not to pay attention to them, for giving in to them is a cause for their entrenchment.