Hi hon, first of all what exactly did the doc who felt the lump say to you about it ? Did she mention it at the exam or did you ask her about it at a subsequent appt? It seems a long time to wait for a mammogram if you saw doc over 2 weeks ago and appt not till April if the doc is concerned about the lump she felt.
I have very dense and large boobs which have caused me much "breast cancer" stress over the years. About 13 years ago, utterly convinced that I was dying from it, my doc sent me for a mammogram and all was clear. The clear advice given to me was to stop prodding and poking my poor breasts as i would make them sore (too true).
Squishy, palpable lumps are not usually a problem - sometimes you can get these when you are hormonal (at certain stages in your cycle) and if you were not prodding and poking you would not even feel them.
Try and relax (easier said than done) and get out there and carry on enjoying yourself. I am sure that the results will not be as dreadful as you are imagining.