Chronic pain can be a real strain on an individual and a relationship as well.
I am not clear on whether youare in therapy to deal with the emotional and psychological toll that this can take, but if you are not, you should think about that.

If you two are great with commmunication, you may actually want to consider couples therapy NOW if you have access- the stress of a chronic physical condition plus if the adhd is particularly severe may take their toll- going to some kind of counseling or therapy together short term will give you both great communication skills.

Having important conversations regarding decisions about your relationship via text is not really the way to go either- there is too much opportunity for misinterpretation and too much potential for distraction.

The sex issue in terms of limitations with chronic pain- there will likely be off and on issues for the entirety of your relationship if this is a chronic long term condition that you have. There are a LOT of ways to get around it, but that requires communication and trust.

You will likely have good and bad periods- but that happens with any person, with any relationship.

I highly recommend having some in depth, face to face conversations and considering some joint counseling, maybe even only a handful of sessions.