Mindfulness with medications and difficult situations With certain antihistamines I get very drowsy and confuse.
I seem to get clingy in these sensations and then when I’m aware of the clinginess, I try to detach the sensations. I just somehow do the opposite of detaching by forcing the detaching and hook up with mind talk.
How to keep mindfulness in these situation? And how to be mindful in difficult situations in general?
What would be the Buddhism direction  on these situation?
Antihistamines have side effects that can include drowsiness or restlessness.
Drowsiness is tough to conquer. Venerable Moggallāna struggled with that a lot even though it was not from antihistamines. Perhaps the longest sutta on drowsiness is AN7.61, which has a list of many things to try:

AN7.61:2.3: “So, Moggallāna, don’t focus on or cultivate the perception that you were meditating on when you fell drowsy.

Discuss your medication with a doctor. Treatments very tremendously between individuals. For example, my allergies were gone after I became a vegetarian. And meditation itself helped:

MN62:5.3: “Rāhula, develop mindfulness of breathing. When mindfulness of breathing is developed and cultivated it’s very fruitful and beneficial.”

In general, whatever you experience, the Buddha's advice to Rahula may help detaching:

MN62:3.2: “Rāhula, you should truly see any kind of form at all—past, future, or present; internal or external; coarse or fine; inferior or superior; far or near: all form—with right understanding: ‘This is not mine, I am not this, this is not my self.’”