This happens all the time with guys starting TRT because their doc gave them too much.
example Crazy Anxiety After First TRT Shot
Usually if they drop the dose and give the body time the heart issues never come back.
You should be able to do the same thing. Try a 200mg/wk for 10 weeks. Divide the shots into 3 so each dose is small. Switch over to subQ instead of IM This will also slow the T dump into your blood.
If you can get thru the 200 for 10 then next cycle try 300 for 12 divided 3 way again to keep the dose low and just keep working up from there.
Good luck
EDIT: It is really a good idea to get bloods ran before your cycle. You need to know how thick (HCT)your blood is before you start because it will get a lot thicker and raise your blood pressure. If your HCT is >49% you should donate a pint of whole blood at the local red cross.