If you look on the Thyroid Uk site they have a list of symptoms and there may be things you are no awhere were thyroid related. Also rwad the other things as well as you may find them helpful. It was take time to get used to any medication and some are more sensitive than others. If I forgot my tabs on a morning I realised by lunch time that I'd missed them which seems illogical as it's a storage hormone and I body converts to to the active T3 when we need it.
So I think you just need a little time to get used to it. But it could be the fillers on the medication that disagree with you. It you look at the Patient Information Leaflet (PIL) it will give you S list of fillers. All tablets have them to bulk up the. Intents and keep them stable. So if after a week or two you are still having problems then take an antihistamine tablet one hour before your thyroid meds and see if that stops the problem
If it does it's the fillers and you need to try a different brand. The pharmacist can help you there but tyhrre are several combinations of fillers and you might not get the right combination to start off with. When you find a brand you are ok with then get your GP to put it on your prescription so the Pharmacy have to get you that one.
Have you been told to go for a retest after 6 weeks? 25 is a very low dose so you may well need more once you are settled on it so retest and if you need some more then again retest after 6 weeks and so on until you are on the correct dose for you. The six weeks is the time it takes your dose to reach the maximum amount in your body as it gradually builds up to that dose so testing and increasing too early can lead to problems and you can end up taking too much which can be unpleasant.
Which brand have you been given? There have been a few adverse commebtsxre the TEVA brand which is thought by many to be a filler issue.
It's a lot to take on board at the start but plenty of help and guidance on here but if the tests the hospital did say yourcthyroid idntvright then you need to continue with the treatment as it could get more of a problem in time so better to get it sorted now.
One other thing to get used to is asking for your blood results. Doctors aren't always good at reading and understanding them so if you have them you can always post them and the ranges for comments. The ranges are important as they differ from lab to lab. That's why it may not be a good thing to suggest to your GP that you stop the medication he may not have the expertise to advise you on that. Give it a go and post any results as you go along and we will help you understand them and can comment.