I am probably not going to be much help because I am not a professional and would hesitate to offer any suggestions re: meds except to ask you if you have reported these reactions to your prescribing doctor . . . A friend was on Paxil and had similar issues and had to be switched to something else. Since it seems that your Paxil has worked for you and the problems appear only with the Effexor, you might be experiencing a reaction or perhaps you need to give your system longer to adjust to the change in meds. Meds work differently for different people and in combination with different other meds. So, most certainly ask your prescribing doctor for other strategies as to when and how to take your meds.
My other suggestion and I do realize that you do not eat breakfast is for you to try something minor for breakfast . . . by eating just at lunch and taking your meds, etc., you may be overwhelming your system and having blood sugar level fluctuations . . . .I know it is difficult to start eating breakfast (I was never a breakfast eater) but I found having something for breakfast helped with managing my anxiety . . .
As for your relationship . . . best wishes for continued happiness with this person . . . his attitude towards your honesty about your anxiety is great but deal with the present . . . by looking at all the possibilities of something that could happen and probably will never happen, you are cheating both yourself and him of the joy of the present moment of building a loving relationship . . . the future will unfold as it will if we nurture the present but by worrying over something that we have no control over does rob us of living in the moment . . . . so my best advice, from someone who is way older than you are, is stay in the moment . . . you may have to work hard at it but it does become easier as the days go on and each of those present moments become building blocks . . . you seem to have great insight so follow up with your doctor and find out about your meds and then live each day with this "best guy" whom you deserve . . . when you can, let us know how things are going . . .take care, kc