Ulnar Neuritis is like hitting your funny bone or feeling like your hand/arm has “gone to sleep on you” - sort of. Its very common with older players in this game at the pitcher’s position. In fact, stress loads that focus on the elbow can strain certain nerve and muscle groups along the arm/elbow and slightly give this feeling (funny bone jitters/arm going to sleep) for a very short period. HOWEVER, if not spotted - the undo stress actions on the arm by a watchful pitching coach, this condition can get worse -Ulnar Neuritis.
As you have already noticed, your arm, elbow and pitching hand are very open to the slightest stress load(s) not properly portioned during your delivery motion, or anything else for that matter. In fact, picking up a bag of groceries, turning a door nob, or even waving good-bey can send a tingle up and down the arm. I’m not saying that you do have this kind of condition - but, if not properly looked after and given time to recoup yourself, your only delaying the rehab process and possibly an adjustment that your body needs to take into account. Your family doctor and/or the specialist in this area can advise you further.
Now to address your situation more directly:
During your therapy, regaining funcitonal, normal use of your arm and hand is usually the course of action here. However, since you didn’t mention any surgery, I assume that your injury - do to stress loads and such, was more to adjust to condition, which is not unusual. Giving yourself time - the body that is, to rest and relax, give the healing process a chance to work, is a good thing.
After February, your preseason starts in high school, and a noticable lack of strength and control should be expected. However, you should have been given “do at home” instructions, along with a set of “reality checks” of the limitations that you’re going to experience. Why? Because of your age, the lack of professional rehab speicalists at your school or on your team to support your come back on the field. In fact, a letter stating everything that I just got through mentioning should have been asked for if not already written out, for your school’s AD and his/her coaching staff. Why? To advise those involved with you at school, to limit your activity and be mindful of your recovery process. I’ve had pitchers that have missed a lot of a season due to related problems that your now facing. However, since I’m not there - you are, your situation could be entirely different than I’m reading into here.
In any event, Give this season a rest. Take stock of the marginal performance that your now showing. You’re not going to improve by fixing your stride, your glove arm, your arm slot, or anything close to those just mentioned. Your body has to adjust to a new impact it wasn’t ready for. And by the way, did anyone mention to you HOW you got this injury so you don’t repeat said same - probably not. On the other hand, if someone has addressed how you got this injury, some one should be watching you very closely so you don’t have a repeat performance - then your right back to square one.
I know what I’m posting here is not what you want to hear. But, I’ve had some experience with things related to what you’re going through. And I’m making my suggestion(s) based on seeing people just like yourself, try to play through an injury like this - without any real pain, just a lack of performance, and the quality of life as they get older doesn’t sit very well.
Because the body can’t absorb adjustments as well as it did when it was younger.
In any event, if you still find a lack of performance as you progress this season, please consider my advice.